Memrise is a British language platform that uses

spaced repetition ''Spaced'' is a British television sitcom created, written by and starring Simon Pegg and Jessica Stevenson, and directed by Edgar Wright, about the comedic, and sometimes surreal and action-packed, misadventures of Daisy Steiner and Tim Bis ...

of flashcards to increase the rate of learning. It is based in London, UK. Memrise offers user-generated content on a wide range of other subjects. The Memrise app has courses in 16 languages and its combinations, while the website for "community courses" has a great many more languages available, including minority and ancient languages. As of 2018, the app had 35 million registered users. Memrise has been profitable since late 2016, having a turnover of $4 million monthly.

History

Memrise was founded by Ed Cooke, a

Grand Master of Memory Grand Master of Memory (GMM) is a title previously awarded by thWorld Memory Sports Councilto people who are able to successfully negotiate the following three memory feats: *Memorise 1,400 random digits in an hour *Memorise the order of 14 decks o ...

; Ben Whately; and Greg Detre, a Princeton neuroscientist specializing in the science of memory and forgetting. The website launched in private beta after winning the

Princeton Princeton University is a private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the Unit ...

Entrepreneurship Club 2009 TigerLaunch competition. In July 2010, Memrise was named as one of the winners of the London Mini-Seedcamp competition. In November 2010, the site was named as one of the finalists for the 2010

TechCrunch TechCrunch is an American global online newspaper focusing on topics regarding high tech, high-tech and Startup company, startup companies. It was founded in June 2005 by Archimedes Ventures, led by partners Michael Arrington and Keith Teare. I ...

Europas Start-up of the Year. In March 2011, it was selected as one of the Techstars Boston startups. In May 2017, Memrise was named as the winner of the "Best App" award at the second edition of the Google Play awards. On 1 October 2012, 100 users were allowed to sign up to test a non-beta version of the website called Memrise 1.0. As of May 2013, a Memrise app has been available for download on both the

App Store (iOS) The App Store is an app marketplace developed and maintained by Apple, for mobile apps on its iOS and iPadOS operating systems. The store allows users to browse and download approved apps developed within Apple's iOS SDK. Apps can be downlo ...

and

Google Play Google Play, also known as the Google Play Store, Play Store, or sometimes the Android Store (and was formerly Android Market), is a digital distribution service operated and developed by Google. It serves as the official app store for certifie ...

. As of January 2020, the app received $21.8 million of investments in a total of seven seed rounds.

Features

Spaced repetition

Memrise makes language studying a

game A game is a structured type of play usually undertaken for entertainment or fun, and sometimes used as an educational tool. Many games are also considered to be work (such as professional players of spectator sports or video games) or art ...

, like its competitor

Duolingo Duolingo, Inc. is an American educational technology company that produces learning Mobile app, apps and provides Language assessment, language certification. Duolingo offers courses on 43 languages, ranging from English language, English, Fre ...

. Memrise uses spaced repetition to accelerate language acquisition. Spaced repetition is an evidence-based learning technique that incorporates increasing intervals of time between subsequent review of previously learned material to exploit the psychological

spacing effect The spacing effect demonstrates that learning is more effective when study sessions are spaced out. This effect shows that more information is encoded into long-term memory by spaced study sessions, also known as '' spaced repetition'' or ''sp ...

. The use of spaced repetition has been shown to increase the rate of memorization.

Community courses

Users of the platform have the ability to create personalized "courses," which consist of curated lists of words and phrases that can be accompanied by audio and pictures. These courses can be used for individual learning purposes or shared with the community by making them publicly available in the course catalogue. This feature has led to the accumulation of a diverse range of "community courses" over time, which has proven useful for studying languages with limited resources or those of niche interest, in addition to the more popular languages. In 2012, less than two years after its launching, Memrise had already crowdsourced materials for about 100 languages, "from Catalan to

Haitian Creole Haitian Creole (; , ; , ), or simply Creole (), is a French-based creole languages, French-based creole language spoken by 10 to 12million people worldwide, and is one of the two official languages of Haiti (the other being French), where it ...

." Courses have been created by enthusiasts to teach

Klingon The Klingons ( ; Klingon language, Klingon: ''tlhIngan'' ) are a humanoid species of aliens in the science fiction franchise ''Star Trek''. Developed by screenwriter Gene L. Coon in 1967 for the Star Trek: The Original Series, original ''Star T ...

Toki Pona Toki Pona (; , , translated as 'the language of good') is a Philosophical language, philosophical, Artistic language, artistic, constructed language designed for its small vocabulary, simplicity, and ease of acquisition. It was created by Canadia ...

, and

Esperanto Esperanto (, ) is the world's most widely spoken Constructed language, constructed international auxiliary language. Created by L. L. Zamenhof in 1887 to be 'the International Language' (), it is intended to be a universal second language for ...

, among other artificial languages.

Classical languages According to the definition by George L. Hart, a classical language is any language with an independent literary tradition and a large body of ancient written literature. Classical languages are usually extinct languages. Those that are still ...

, such as

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

and

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

, have been covered as well. In

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

, the Department of Education of

Keelung City Government The Keelung City Government (KLCG; ) is the municipal government of Keelung, Taiwan. Organization * Chief Secretary * Department of Civil Affairs * Department of Finance * Department of Economic Affairs * Department of Education * Department ...

has taken initiatives to foster the education of indigenous and local languages by publishing Memrise-based learning materials for the Amis, Taroko,

Taiwanese Hakka Taiwanese Hakka is a language group consisting of Hakka dialects spoken in Taiwan, and mainly used by people of Hakka ancestry. Taiwanese Hakka is divided into five main dialects: Sixian, Hailu, Dabu, Raoping, and Zhao'an. The most widel ...

, and

Taiwanese Hokkien Taiwanese Hokkien ( , ), or simply Taiwanese, also known as Taigi ( zh, c=臺語, tl=Tâi-gí), Taiwanese Southern Min ( zh, c=臺灣閩南語, tl=Tâi-uân Bân-lâm-gí), Hoklo and Holo, is a variety of the Hokkien language spoken natively ...

languages. Journalist

Joshua Foer Joshua Foer (born September 23, 1982) is a freelance journalist and author living in Brookline, Massachusetts, with a primary focus on science. He was the 2006 USA Memory Champion, which was described in his 2011 book, '' Moonwalking with Eins ...

, in an attempt to communicate with the

Pygmy peoples In anthropology, pygmy peoples are ethnic groups whose average height is unusually short. The term pygmyism is used to describe the phenotype of endemic short stature (as opposed to disproportionate dwarfism occurring in isolated cases in a po ...

in the

Congo Basin The Congo Basin () is the sedimentary basin of the Congo River. The Congo Basin is located in Central Africa, in a region known as west equatorial Africa. The Congo Basin region is sometimes known simply as the Congo. It contains some of the larg ...

, was able to pick up

Lingala Lingala (or Ngala, Lingala: ) is a Bantu languages, Bantu language spoken in the northwest of the Democratic Republic of the Congo, the northern half of the Republic of the Congo, in their capitals, Kinshasa and Brazzaville, and to a lesser de ...

, a language with scarce learning materials, by utilizing community courses.

Speech communities Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...

endangered languages An endangered language or moribund language is a language that is at risk of disappearing as its speakers die out or shift to speaking other languages. Language loss occurs when the language has no more native speakers and becomes a " dead langua ...

have made use of the platform to aid in their revitalization endeavors, as seen in the case of Ume Sámi, a language spoken by fewer than 50 people in Sweden. In the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, indigenous nations have published courses on Memrise to support efforts to revitalize their heritage languages, including

Cherokee The Cherokee (; , or ) people are one of the Indigenous peoples of the Southeastern Woodlands of the United States. Prior to the 18th century, they were concentrated in their homelands, in towns along river valleys of what is now southwestern ...

, Seneca,

Comanche The Comanche (), or Nʉmʉnʉʉ (, 'the people'), are a Tribe (Native American), Native American tribe from the Great Plains, Southern Plains of the present-day United States. Comanche people today belong to the List of federally recognized tri ...

Potawatomi The Potawatomi (), also spelled Pottawatomi and Pottawatomie (among many variations), are a Native American tribe of the Great Plains, upper Mississippi River, and western Great Lakes region. They traditionally speak the Potawatomi language, ...

, and

Choctaw The Choctaw ( ) people are one of the Indigenous peoples of the Southeastern Woodlands of the United States, originally based in what is now Louisiana, Mississippi and Alabama. The Choctaw language is a Western Muskogean language. Today, Choct ...

. The success of this project "inspired the start of similar projects among speakers of other Indigenous languages," like ''Unangam Qilinĝingin'' to teach the

Aleut language Aleut ( ) or is the language spoken by the Aleut living in the Aleutian Islands, Pribilof Islands, Commander Islands, and the Alaska Peninsula (in Aleut , the origin of the state name Alaska). Aleut is the sole language in the Aleut branch of ...

spoken in

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

. Courses of many other endangered languages can be found, including the other

Sámi languages The Sámi languages ( ), also rendered in English language, English as Sami and Saami, are a group of Uralic languages spoken by the Indigenous Sámi peoples in Northern Europe (in parts of northern Finland, Norway, Sweden, and extreme northwest ...

, Hawaiian,

Yiddish Yiddish, historically Judeo-German, is a West Germanic language historically spoken by Ashkenazi Jews. It originated in 9th-century Central Europe, and provided the nascent Ashkenazi community with a vernacular based on High German fused with ...

, Cornish, Greenlandic,

Navajo The Navajo or Diné are an Indigenous people of the Southwestern United States. Their traditional language is Diné bizaad, a Southern Athabascan language. The states with the largest Diné populations are Arizona (140,263) and New Mexico (1 ...

, Irish, and

Welsh Welsh may refer to: Related to Wales * Welsh, of or about Wales * Welsh language, spoken in Wales * Welsh people, an ethnic group native to Wales Places * Welsh, Arkansas, U.S. * Welsh, Louisiana, U.S. * Welsh, Ohio, U.S. * Welsh Basin, during t ...

. The Institute on Collaborative Language Research, founded at the

University of California The University of California (UC) is a public university, public Land-grant university, land-grant research university, research university system in the U.S. state of California. Headquartered in Oakland, California, Oakland, the system is co ...

, organized a workshop in 2018 to teach participants to use Memrise for teaching and learning endangered languages with the aim of revitalization, considering that Memrise is "an ideal tool for language revitalization because it’s flexible, community-oriented, easy-to-use, fun, and free" and "a great way for fluent elders and more tech-savvy young people to collaborate on a revitalization project". A research conducted by NEȾOLṈEW̱, a Canadian partnership working on indigenous language revitalization, praises the motivational effect of Memrise' leaderboard for learners, but raises concerns about the issue of

data sovereignty Data sovereignty means that data generated within a country’s borders is governed by that nation’s laws and regulatory frameworks; this ensures local control over data access, storage, and usage. In other words, a country is able to control a ...

. In 2023, the successes of the Memrise projects for Ume Sámi and Kristang were cited as "inspiring stories" by the

UNESCO The United Nations Educational, Scientific and Cultural Organization (UNESCO ) is a List of specialized agencies of the United Nations, specialized agency of the United Nations (UN) with the aim of promoting world peace and International secur ...

publication ''Digital initiatives for indigenous languages''. Apart from resources for language learning, the community has produced courses for other subject matters, including geography, history, mathematics, natural science, some designed for general interests and some for

test preparation Test preparation (abbreviated test prep) or exam preparation is an educational course, tutoring service, educational material, or a learning tool designed to increase students' performance on standardized tests. Examples of these tests include ...

. In July 2024, Memrise announced in a blog-post that community courses will be removed from their new app experience, moving them to a separate platform.

"Mems"

Memrise used to have a function known as "mems," which are user-generated mnemonic devices or memory aids to help learners remember and retain new information more effectively. Mems are often designed to be humorous or even absurd to be memorable, such as using a picture of

Abraham Lincoln Abraham Lincoln (February 12, 1809 – April 15, 1865) was the 16th president of the United States, serving from 1861 until Assassination of Abraham Lincoln, his assassination in 1865. He led the United States through the American Civil War ...

listening to a

ghetto blaster A boombox is a transistorized portable music player featuring one or two cassette tape players/recorders and AM/FM radio, generally with a carrying handle. Beginning in the mid-1990s, a CD player was often included. Sound is delivered throu ...

with the caption "Abe ends work in the evening" for the German word Abend, which means "evening". For learning

Chinese characters Chinese characters are logographs used Written Chinese, to write the Chinese languages and others from regions historically influenced by Chinese culture. Of the four independently invented writing systems accepted by scholars, they represe ...

, mems have been created to help relate their meaning and the concept they represent. In 2012, Ed Cooke highlighted the

network effect In economics, a network effect (also called network externality or demand-side economies of scale) is the phenomenon by which the Value (economics), value or utility a user derives from a Goods, good or Service (economics), service depends on th ...

associated with learning through mems, explaining that "the more people on the site, the more there are contributing new content for the mems". In 2013, Ben Whately and Ed Cooke discussed their team's approach to take advantage of the Internet obsession with cats and "the relationship between cuteness and improved cognitive function" to create memorable mems. However, since September 2022, mems have been completely removed from the site, despite overwhelmingly negative feedback from users as expressed in the official forum.

Official courses

As of February 2025, Memrise has official materials for 35 languages for English speakers.These languages are:

Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...

Chinese Chinese may refer to: * Something related to China * Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity **Han Chinese, East Asian ethnic group native to China. **'' Zhonghua minzu'', the supra-ethnic ...

, Danish,

Dutch Dutch or Nederlands commonly refers to: * Something of, from, or related to the Netherlands ** Dutch people as an ethnic group () ** Dutch nationality law, history and regulations of Dutch citizenship () ** Dutch language () * In specific terms, i ...

French French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), ...

, Galician,

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

Hausa Hausa may refer to: * Hausa people, an ethnic group of West Africa * Hausa language, spoken in West Africa * Hausa Kingdoms, a historical collection of Hausa city-states * Hausa (horse) or Dongola horse, an African breed of riding horse See also ...

Hebrew Hebrew (; ''ʿÎbrit'') is a Northwest Semitic languages, Northwest Semitic language within the Afroasiatic languages, Afroasiatic language family. A regional dialect of the Canaanite languages, it was natively spoken by the Israelites and ...

Hindi Modern Standard Hindi (, ), commonly referred to as Hindi, is the Standard language, standardised variety of the Hindustani language written in the Devanagari script. It is an official language of India, official language of the Government ...

, Icelandic,

Igbo Igbo may refer to: * Igbo people, an ethnic group of Nigeria * Igbo language, their language * anything related to Igboland, a cultural region in Nigeria See also * Ibo (disambiguation) * Igbo mythology * Igbo music * Igbo art * * Igbo-Ukwu, a t ...

Indonesian Indonesian is anything of, from, or related to Indonesia, an archipelagic country in Southeast Asia. It may refer to: * Indonesians, citizens of Indonesia ** Native Indonesians, diverse groups of local inhabitants of the archipelago ** Indonesian ...

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, a Romance ethnic group related to or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance languag ...

Korean Korean may refer to: People and culture * Koreans, people from the Korean peninsula or of Korean descent * Korean culture * Korean language **Korean alphabet, known as Hangul or Korean **Korean dialects **See also: North–South differences in t ...

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

Mongolian Mongolian may refer to: * Something of, from, or related to Mongolia, a country in Asia * Mongolian people, or Mongols * Bogd Khanate of Mongolia, the government of Mongolia, 1911–1919 and 1921–1924 * Mongolian language * Mongolian alphabet * ...

, Norwegian,

Persian Persian may refer to: * People and things from Iran, historically called ''Persia'' in the English language ** Persians, the majority ethnic group in Iran, not to be conflated with the Iranic peoples ** Persian language, an Iranian language of the ...

Polish Polish may refer to: * Anything from or related to Poland, a country in Europe * Polish language * Polish people, people from Poland or of Polish descent * Polish chicken * Polish brothers (Mark Polish and Michael Polish, born 1970), American twin ...

, Portuguese (

European European, or Europeans, may refer to: In general * ''European'', an adjective referring to something of, from, or related to Europe ** Ethnic groups in Europe ** Demographics of Europe ** European cuisine, the cuisines of Europe and other West ...

and Brazilian varieties),

Russian Russian(s) may refer to: *Russians (), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *A citizen of Russia *Russian language, the most widely spoken of the Slavic languages *''The Russians'', a b ...

, Slovenian, Somali,

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many countries in the Americas **Spanish cuisine **Spanish history **Spanish culture ...

( Castilian and

Mexican Mexican may refer to: Mexico and its culture *Being related to, from, or connected to the country of Mexico, in North America ** People *** Mexicans, inhabitants of the country Mexico and their descendants *** Mexica, ancient indigenous people ...

varieties),

Swahili Swahili may refer to: * Swahili language, a Bantu language officially used in Tanzania, Kenya and Uganda and widely spoken in the African Great Lakes. * Swahili people, an ethnic group in East Africa. * Swahili culture, the culture of the Swahili p ...

Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...

, Thai,

Turkish Turkish may refer to: * Something related to Turkey ** Turkish language *** Turkish alphabet ** Turkish people, a Turkic ethnic group and nation *** Turkish citizen, a citizen of Turkey *** Turkish communities in the former Ottoman Empire * The w ...

, Ukrainian,

Vietnamese Vietnamese may refer to: * Something of, from, or related to Vietnam, a country in Southeast Asia * Vietnamese people, or Kinh people, a Southeast Asian ethnic group native to Vietnam ** Overseas Vietnamese, Vietnamese people living outside Vietna ...

Xhosa Xhosa may refer to: * Xhosa people, a nation, and ethnic group, who live in south-central and southeasterly region of South Africa * Xhosa language, one of the 11 official languages of South Africa, principally spoken by the Xhosa people See als ...

, and Yoruba. Materials have also been developed for speakers of Arabic,Available languages:

English English usually refers to: * English language * English people English may also refer to: Culture, language and peoples * ''English'', an adjective for something of, from, or related to England * ''English'', an Amish ter ...

(

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

and

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

varieties), French, German, Korean, Spanish, Swedish, Turkish. Chinese,Available languages: English (British and American varieties), French, German, Japanese, Korean, Russian, Spanish. Dutch,Available languages: English (British variety), French, Italian, Japanese, Korean, Spanish. French,Available languages: English (British and American varieties), Chinese, German, Japanese, Korean, Russian, Slovenian, Spanish. German, Hindi, Indonesian, Italian, Japanese, Korean, Norwegian, Polish, Portuguese, Russian, Spanish, Swedish, Turkish, and Vietnamese. Starting from 2023, the official courses are combined with a

GPT-3 Generative Pre-trained Transformer 3 (GPT-3) is a large language model released by OpenAI in 2020. Like its predecessor, GPT-2, it is a decoder-only transformer model of deep neural network, which supersedes recurrence and convolution-based ...

-powered "AI Language partner" that allows learners to practice human-like conversations, which Memrise believes can help learners to overcome the "confidence gap" in language acquisition. Official courses do not cover the vast majority of languages included in community courses, nor are there any non-language-related official materials.

Gamification elements

In late September 2012, the leaderboard on the website was temporarily suspended due to "extensive cheating". Specific users had been using bots and non-intensive mechanisms, such as celebrity photo memory courses, to achieve atypical scores that were not reflective of actual learning. In response, the administrators established a new leaderboard after revising the scoring loopholes.

Declining support for community-created content

Over time, Memrise, initially established as a learning platform centered around

crowdsourcing Crowdsourcing involves a large group of dispersed participants contributing or producing goods or services—including ideas, votes, micro-tasks, and finances—for payment or as volunteers. Contemporary crowdsourcing often involves digit ...

and community engagement, has undergone a noticeable transition by gradually phasing out significant features in favor of prioritizing their official content offerings.

The creation of "Decks" to separate community courses in 2019

In late February 2019, Memrise announced that user-created content will be moving to a different web-based platform. It was announced that this new website would not have an app and that users would be unable to access their material offline. On 25 February 2020, as a response to the loud criticism from users, Memrise decided to undo the split (i.e. closing Decks and merging its content back to the Memrise main site.)

Second separation of community courses from the main website in 2024

However, in November 2023, Memrise announced on a forum post that it planned to "sunset" user-created courses. The very forum was closed on 8 December 2023 as the company shifts its focus from supporting community-created content to developing a new "experience" based on official content. In February 2024, Memrise has again separated community courses to a new website, which is not accessible through the updated mobile app, meaning that users can no longer download the courses for offline accessibility. The official notice states that the courses will remain on the new website until "at least the end of 2024". The CEO Steve Toy has made posts announcing and trying to explain the abovementioned change on the Memrise

subreddit Reddit ( ) is an American Proprietary software, proprietary social news news aggregator, aggregation and Internet forum, forum Social media, social media platform. Registered users (commonly referred to as "redditors") submit content to the ...

, under which many users have expressed concerns, frustrations, and even anger regarding the future of community courses. Regarding the future of community courses, Toy has clarified that he has no plan to take them down after 2024 or any date, but is "not prepared to put isname next to a promise about the site slongevity at this moment." As of March 2025, community courses are still available on the website.

Notes

References

External links

*
iTunes App Store

Google Play
{{Spaced repetition British educational websites Spaced repetition software Mnemonics Crowdsourcing Internet properties established in 2010 Language education in the United Kingdom Language-learning websites Proprietary language learning software Android (operating system) software Social networking language-learning websites Language learning software Companies based in London IOS software Multilingual websites Proprietary multilingual software Education companies established in 2010 Language revival Native American language revitalization Esperanto education Educational apps