A mobile application or app is a computer program or software application designed to run on a mobile device such as a phone, tablet, or watch. Mobile applications often stand in contrast to desktop applications which are designed to run on desktop computers, and web applications which run in mobile web browsers rather than directly on the mobile device.

Mobile application development is the process of making software for smartphones, tablets and digital assistants, most commonly for the Android and iOS operating systems. The software can be preinstalled on the device, downloaded from a mobile app store or accessed through a mobile web browser.

Mobile apps are designed with consideration for the demands and constraints of the devices and also to take advantage of any specialized capabilities they have.