A mobile app (an abbreviation for the technical term application) is a piece of software for mobile devices or mobile operating systems. Although the term app refers to any kind of application software, in the English-speaking world it is often equated with application software for smartphones and tablets. In the case of mobile apps, a distinction is made between native apps, which only work on one platform, and platform-independent web, hybrid and cross-platform apps.
They are available for a wide variety of areas. These range from the simplest utilities and fun applications with only one function to program packages with extensive functionality (e.g. office applications, games, guidebooks, fitness apps, for emulating older home computers and programmable calculators, as an aid for diabetics and much more). Mobile remote apps are increasingly being used to remotely control digital devices such as cameras, action camcorders or quadrocopters. The majority of these apps are free of charge, a smaller part has to be purchased, usually for small amounts, in the respective App Store.
Apple App Store
The App Store is a digital distribution platform for applications (software). The platform was launched by Apple in 2008 and offers mobile apps for iOS (iPhone, iPad, …) devices and software for tvOS and watchOS.
The App Store builds on the infrastructure of the iTunes Store. To buy and manage apps, you need the App Store or iTunes software.
For a better overview, there are more than 20 categories, including entertainment, finance, games, health and fitness, books, news, social networking, and utilities. A search function and various hit lists are intended to facilitate orientation through the offering as well as ratings (1 to 5 stars) and comments from other users of the programs.
If the App Store is accessed directly via iPhone, iPad or iPod touch, the app is installed directly on the device and the program is added to the iTunes library the next time it is synchronized with the home computer. For apps with less than 100 MB, which is the case for most of the apps except for many games, the iPhone can be used to download the app directly over the mobile network. Larger applications require an active Internet connection via WLAN.
Up to version 12.6, the App Store could be accessed via the iTunes media player, allowing users to buy programs for their iPhone, iPod touch or iPad with their PC. With this variant, the downloaded apps were first added to the iTunes media library and then automatically transferred to the connected mobile device during the next synchronization. This feature has not been available since version 12.7 of September 2017.
Apple can delete applications on the iPhone that have been downloaded from the App Store. When the user goes online, iPhone automatically contacts an Apple server and sends a list of all installed apps. These can then be remotely deleted by Apple.
The programs offered in the App Store are to a large extent not from Apple itself, but from third-party providers and free software developers. Apps developers can submit them via iTunes Connect, but Apple reserves the right to decline them after reviewing them. Apple offers the iOS-SDK free of charge together with the development environment Xcode, which can only be used on macOS. According to Apple, there were already over 125,000 developers by the end of 2009. To publish an app in the App Store, you need to register with the iOS Developer Program for a fee. The price for the app can be freely selected by the developer according to predefined price levels. Apple retains 30 percent of this fee.
The App Store is the only official way to transfer third-party applications and games to your iPhone, iPad, or iPod touch. Apple promises protection against malware. Software that does not originate from the App Store can only be installed after a modification of the operating system (so-called jailbreak). The installed installation programs, the most common of which is Cydia, allow access to other software platforms, especially the so-called App Repository. The proportion of users who have installed such alternative programs is relatively small. According to a study by a private company, the proportion of iPhones modified in this way was around 9 percent in August 2009.