Definition of App store:
(A trademark for) a facility (especially one which is itself an app) from which users can download apps for smartphones, tablet computers, etc.
An online marketplace where users of smartphones and other mobile devices can browse, purchase, and download applications, or apps, that augment the capabilities of their devices. While Apple, Inc. created the original App Store for iPhone apps, and claims copyright to the term, online stores selling mobile apps for other platforms are also referred to as app stores.
Meaning of App store & App store Definition