App

App means application. It is an abbreviation that refers to a software application, usually an application for a mobile device such as an iPhone or an Android phone.

The abbreviation grew a lot in popularity due to the rise of mobile devices and the applications that run on them. You can purchase iOS apps from the iTunes store for iPhones and Android apps from the Google Play store for Android phones. You can also download and install Windows apps from the Microsoft store for Windows Phones, although these apps are a lot less popular than iOS and Android apps.

App is an abbreviation for "appreciate" and is typically used online, in texts, and emails. It is used for conveying appreciation for someone, as in, "I app your concern."

App may also be an abbreviation for "appreciation". Beware though, the abbreviation may be confusing for some since "app" is more commonly used for "application".