mobile compatibility

Windows is the only environment with complete desktop/tablet software compatibility. Except for BlackBerry, which runs Android apps in addition to its native programs, all other devices (iOS, Android and Windows) run apps created for their platforms only.

Windows Tablets Are Windows PCs
The most significant change in tablet compatibility in more than two decades was Windows, starting with Windows 8. All Windows desktop/laptop apps can also run on Windows tablets. Although Windows tablets were not new, the thin, lightweight Windows 8 tablet was a departure from Windows tablets in the past (see Tablet PC). The hybrid and convertible styles are also appealing. See hybrid laptop and Windows tablet.

Phone/Tablet Compatibility
iPhone apps run in iPad tablets, and Android phone apps run in Android tablets. Using different methods, iPads and Android tablets can scale apps to fill the screen. Small developers only need to create one version, users with phones and tablets only have to buy the one app. In many cases, however, separate phone and tablet apps are necessary. See mobile device vendor control and how to select a mobile device.

Windows Mobile Compatibility

Although Windows code is shared among all Windows platforms, in order to support all Windows mobile devices, vendors must publish a phone app and a desktop/tablet app. Windows RT tablets are no longer supported. See Windows Phone, Windows RT and Windows 8.

Desktop-Mobile Compatibility

Windows apps run on Windows tablets, but Mac apps do not run on Apple's mobile devices (see iOS).

Smartphone-Tablet Compatibility

Even if the same app runs in both phone and tablet, the chances are that a tablet version will be created to use the larger screen.