An
app store (or
app marketplace) is a type of
digital distribution platform for computer software, often in a mobile context. Apps provide a specific set of functions which, by definition, do not include the running of the computer itself. Apps are designed to run on specific devices, and are written for a specific
operating system (such as
iOS,
Mac OS X,
Windows, or
Android). Complex software designed for use on a
personal computer, for example, may have a related app designed for use on a
mobile device.