Mobile app development is the act or process by which a

mobile app A mobile application or app is a computer program or software application designed to run on a mobile device such as a smartphone, phone, tablet computer, tablet, or smartwatch, watch. Mobile applications often stand in contrast to desktop appli ...

is developed for one or more

mobile device A mobile device or handheld device is a computer small enough to hold and operate in hand. Mobile devices are typically battery-powered and possess a flat-panel display and one or more built-in input devices, such as a touchscreen or keypad. ...

s, which can include

personal digital assistant A personal digital assistant (PDA) is a multi-purpose mobile device which functions as a personal information manager. Following a boom in the 1990s and 2000s, PDAs were mostly displaced by the widespread adoption of more highly capable smar ...

s (PDA), enterprise digital assistants (EDA), or

mobile phone A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This rad ...

s. Such software applications are specifically designed to run on mobile devices, after considering many hardware constraints. Common constraints include

central processing unit A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary Processor (computing), processor in a given computer. Its electronic circuitry executes Instruction (computing), instructions ...

(CPU) architecture and speeds, available

random-access memory Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows ...

(RAM), limited data storage capacities, and considerable variation in displays (technology, size, dimensions, resolution) and input methods (buttons, keyboards, touch screens with or without styluses). These applications (or 'apps') can be pre-installed on phones during manufacturing or delivered as web applications, using server-side or client-side processing (e.g.,

JavaScript JavaScript (), often abbreviated as JS, is a programming language and core technology of the World Wide Web, alongside HTML and CSS. Ninety-nine percent of websites use JavaScript on the client side for webpage behavior. Web browsers have ...

) to provide an "application-like" experience within a

web browser A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's scr ...

. The mobile app development sector has experienced significant growth in Europe. A 2017 report from the Progressive Policy Institute estimated there were ''1.89 million jobs'' in the ''app economy'' across the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

(EU) by January 2017, marking a 15% increase from the previous year. These jobs include roles such as mobile app developers and other positions supporting the app economy.

Overview

To facilitate developing applications for mobile devices, and the consistency thereof, various approaches have been taken. Most companies that ship a product (e.g., Apple, iPod/iPhone/iPad) provide an official software development kit (SDK). They may also opt to provide some form of

software testing Software testing is the act of checking whether software satisfies expectations. Software testing can provide objective, independent information about the Quality (business), quality of software and the risk of its failure to a User (computin ...

and/or

quality assurance Quality assurance (QA) is the term used in both manufacturing and service industries to describe the systematic efforts taken to assure that the product(s) delivered to customer(s) meet with the contractual and other agreed upon performance, design ...

(QA). In exchange for being provided the SDK or other tools, it may be necessary for a prospective developer to sign some form of non-disclosure agreement (NDA), which restricts the sharing of privileged information. As part of the development process, mobile

user interface In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine fro ...

(UI) design is an essential step in the creation of mobile apps. Mobile UI designers consider constraints, contexts, screen space, input methods, and mobility as outlines for design. Constraints in mobile UI design, which include the limited attention span of the user and form factors such as a mobile device's screen size for a user's hand(s). Mobile UI context includes signal cues from user activity, such as the location where or the time when the device is in use, that can be observed from user interactions within a mobile app. Such context clues can be used to provide automatic suggestions when scheduling an appointment or activity or to filter a list of various services for the user. The user is often the focus of interaction with their device, and the interface entails components of both hardware and software. User input allows for the users to manipulate a system, and the device's output allows the system to indicate the effects of the users' manipulation. Overall, mobile UI design's goal is mainly for an understandable, user-friendly interface. Functionality is supported by mobile enterprise application platforms or

integrated development environment An integrated development environment (IDE) is a Application software, software application that provides comprehensive facilities for software development. An IDE normally consists of at least a source-code editor, build automation tools, an ...

s (IDEs). Developers of mobile applications must also consider a large array of devices with different screen sizes, hardware specifications, and configurations because of intense competition in mobile hardware and changes within each of the platforms. Today, mobile apps are usually distributed via an official online outlet or marketplace (e.g., Apple: The App Store – Google: Google Play) and there is a formalized process by which developers submit their apps for approval and inclusion in those marketplaces. Historically, however, that was not always the case. Mobile UIs, or front-ends, rely on mobile back-ends to support access to enterprise systems. The mobile back-end facilitates data routing, security, authentication, authorization, working off-line, and service orchestration. This functionality is supported by a mix of middleware components, including mobile app servers, mobile backend as a service (MBaaS), and service-oriented architecture (SOA) infrastructure.

Platform

The software development packages needed to develop, deploy, and manage

s are made from many components and tools which allow a developer to write, test, and deploy applications for one or more target platforms.

Front-end development tools

Front-end development tools are focused on the user interface and user experience (UI-UX) and provide the following abilities: * UI design tools * SDKs to access device features * Cross-platform accommodations/support Notable tools are listed below.

First party

First party tools include official SDKs published by, or on behalf of, the company responsible for the design of a given hardware platform (e.g., Apple, Google, etc.), and any third-party software that is officially supported for the purpose of developing mobile apps for that hardware.

Second party

Third party

Back-end servers

Back-end tools pick up where the front-end tools leave off, and provide a set of reusable services that are centrally managed and controlled and provide the following abilities: * Integration with back-end systems * User authentication-authorization * Data services * Reusable business logic Available tools include:

Security add-on layers

With

bring your own device Bring your own device (BYOD ) (also called bring your own technology (BYOT), bring your own phone (BYOP), and bring your own personal computer (BYOPC)) refers to being allowed to use one's personally owned device, rather than being required to use ...

(BYOD) becoming the norm within more enterprises, IT departments often need stop-gap, tactical solutions that layer atop existing apps, phones, and platform component. Features include * App wrapping for security * Data encryption * Client actions * Reporting and statistics

System software

Many system-level components are needed to have a functioning platform for developing mobile apps. Criteria for selecting a development platform usually include the target mobile platforms, existing infrastructure, and development skills. When targeting more than one platform with cross-platform development, it is also important to consider the impact of the tool on the user experience. Performance is another important criterion, as research on mobile apps indicates a strong correlation between application performance and user satisfaction. Along with performance and other criteria, the availability of the technology and the project's requirements may drive the development between native and cross-platform environments. To aid the choice between native and cross-platform environments, some guidelines and benchmarks have been published. Typically, cross-platform environments are reusable across multiple platforms, leveraging a native container while using HTML, CSS, and JavaScript for the user interface. In contrast, native environments are targeted at one platform for each of those environments. For example, Android development occurs in the Eclipse IDE using Android Developer Tools (ADT) plugins, Apple iOS development occurs using the Xcode IDE with Objective-C and/or Swift, Windows and BlackBerry each have their own development environments.

Mobile app testing

Mobile applications are first tested within the development environment using emulators and later subjected to field testing.

Emulator In computing, an emulator is Computer hardware, hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run sof ...

s provide an inexpensive way to test applications on mobile phones to which developers may not have physical access. The following are examples of tools used for testing applications across the most popular

mobile operating system A mobile operating system is an operating system used for smartphones, tablets, smartwatches, smartglasses, or other non-laptop personal mobile computing devices. While computers such as laptops are "mobile", the operating systems used on the ...

s. * ''Google Android Emulator'' – an Android emulator that is patched to run on a Windows PC as a standalone app, without having to download and install the complete and complex Android SDK. It can be installed and Android compatible apps can be tested on it. * ''The official Android SDK Emulator'' – a mobile device emulator which mimics all of the hardware and

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

features of a typical mobile device (without the calls). * ''TestiPhone'' – a

-based simulator for quickly testing

iPhone The iPhone is a line of smartphones developed and marketed by Apple that run iOS, the company's own mobile operating system. The first-generation iPhone was announced by then–Apple CEO and co-founder Steve Jobs on January 9, 2007, at ...

web applications. This tool has been tested and works using

Internet Explorer 7 Windows Internet Explorer 7 (IE7) (codenamed Rincon) is a version of Internet Explorer, a web browser for Windows. It was released by Microsoft on October 18, 2006. It was the first major update to the browser since 2001. It does not support ve ...

, Firefox 2 and Safari 3. * ''iPhoney'' – gives a

pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, p ...

-accurate web browsing environment and it is powered by

Safari A safari (; originally ) is an overland journey to observe wildlife, wild animals, especially in East Africa. The so-called big five game, "Big Five" game animals of Africa – lion, African leopard, leopard, rhinoceros, African elephant, elep ...

. It can be used while developing

web sites A website (also written as a web site) is any web page whose content is identified by a common domain name and is published on at least one web server. Websites are typically dedicated to a particular topic or purpose, such as news, education, ...

for the

. It is not an iPhone simulator but instead is designed for web developers who want to create 320 by 480 (or 480 by 320) websites for use with iPhones. iPhoney will only run on

OS X macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

10.4.7 or later. * ''BlackBerry Simulator'' – There are a variety of official BlackBerry simulators available to emulate the functionality of actual BlackBerry products and test how the device software, screen, keyboard and trackwheel will work with the application. * ''Windows UI Automation'' – To test applications that use the Microsoft UI Automation technology, it requires Windows Automation API 3.0. It is pre-installed on Windows 7, Windows Server 2008 R2 and later versions of Windows. On other operating systems, you can install it using Windows Update or download it from the

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

Web site. * ''MobiOne Developer'' – a

mobile Web The mobile web comprises mobile browser-based World Wide Web services accessed from handheld mobile devices, such as smartphones or feature phones, through a mobile network, mobile or other wireless network. History and development Traditiona ...

(IDE) for

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

that helps developers to code, test, debug, package and deploy mobile

Web application A web application (or web app) is application software that is created with web technologies and runs via a web browser. Web applications emerged during the late 1990s and allowed for the server to dynamically build a response to the request, ...

s to devices such as

BlackBerry BlackBerry is a discontinued brand of handheld devices and related mobile services, originally developed and maintained by the Canadian company Research In Motion (RIM, later known as BlackBerry Limited) until 2016. The first BlackBerry device ...

, Android, and the Palm Pre. MobiOne Developer was officially declared End of Life by the end of 2014. Tools include * Eggplant Functional – GUI-based automated test tool for mobile apps across all operating systems and devices * Ranorex – Test automation tools for mobile, web and desktop apps * Testdroid – Real mobile devices and test automation tools for testing mobile and web apps

Design principles

According to a 2020 Industry Report on Applications, 46% of

users have stated that they have stopped using or uninstalled an app due to poor performance. Design experts advocate for the following design principles to create successful and effective mobile apps: ''Clutter-free screens'' – Keeps interactions quick and simple, allowing users to focus on one specific task rather than being overwhelmed with multiple features and tasks. Design experts strongly advocate for one task per screen and recommend breaking down long forms into pages and progressively revealing new tasks or fields to minimize clutter. ''Reduce cognitive load'' – Makes the use of the app as seamless as possible, and preserves natural flow through the app. Design experts suggest incorporating

autocomplete Autocomplete, or word completion, is a feature in which an application software, application predicts the rest of a word a user is typing. In Android (operating system), Android and iOS smartphones, this is called predictive text. In graphical us ...

, spell-check, predictive text assistance, and dropdown menus to reduce cognitive load. Design experts also recommend the state of the app be preserved when users temporarily leave the app and re-enter so that users can continue their use from where they left off. ''Simple navigation'' – Around 11% of people have uninstalled apps due to their complicated interface. Design experts state it is paramount to present the navigation bar visibly in your app to help users navigate to frequently used and high-priority screens instantly. They suggest the use of recognizable icons specific to the device operating system to help users easily take actions such as opening a menu, changing settings, going back a screen, and searching within a page. According to them, a user should not be confused while navigating the app, so an orderly, clear, and logical navigation flow drives engagement and discovery in the app. ''Notifications'' – It’s reported that around 19% of users uninstall an app due to frequent push notifications. Notifications should be sent with careful planning according to design experts. Experts state notifications should be sent at a time most convenient to users in their time zone and the messages should be personalized to bring great value to them. ''Speed appearance'' – About 19% of people uninstall apps due to hang up issues. Design experts state it’s important to make sure the app is fast and responsive so that users don’t have to wait for content. They state developers should deliver content faster or give the perception of progress. Some approaches suggested by the experts are the use of skeleton screens which show the layout of the app with content grayed out, progress bars or loading spinners, tasks being carried out in the background and delivering the content quickly when the user requests for it, or giving users some tasks or content while they are waiting for a page to load. ''Usability'' – Approximately 85% of mobile users use their phone with one hand, thus design experts state it is important that the top-level menu, frequently used controls, and common action items are within the reach of the user’s thumb. They also stress the importance of readability and it’s recommended that the text size is at least 11 point font so that users can read it at the typical reading distance without zooming in. It is recommended that headers and titles on the app screens be

San Francisco San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of ...

17pt and Roboto 16sp for operating systems iOS and Android respectively. The experts also state there should be 4.5:1 minimum contrast ratio between text and the background color. Design experts strongly encourage developers to make apps accessible for all users including people with

disabilities Disability is the experience of any condition that makes it more difficult for a person to do certain activities or have equitable access within a given society. Disabilities may be cognitive, developmental, intellectual, mental, physica ...

, so they suggest features such as voice navigation,

screen reader A screen reader is a form of assistive technology (AT) that renders text and image content as speech or braille output. Screen readers are essential to blindness, blind people, and are useful to visually impaired people, Illiteracy, illiterate, ...

compatibility, and user interface adaptability in mobile apps.

Patents

Many patent applications are pending for new mobile phone apps. Most of these are in the technological fields of business methods, database management, data transfer, and operator interface.Nowotarski et al., "Increasing Allowance Rates by Selectively Targeting Patent Class" IPwatchdog, April 6, 2011
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References

{{Mobile phones fr:Application mobile pl:Aplikacje mobilne fi:Mobiiliohjelmisto