Web app manifest file used by Firefox OS apps to identify important details of an app; contains information in JSON format about an app, which includes the name, developer, launch path, description, and icon(s); also contains a list of web APIs that the app requires.

Firefox OS is an open source mobile operating system developed by Mozilla. Firefox OS apps are similar to websites or web apps and are built with standard web technologies such as HTML, JavaScript, and CSS. They can be accessed through a web browser and can also be installed on devices for working offline. The list of web APIs contained within the WEBAPP file allows you to make decisions about apps before installing them. WEBAPP files are necessary in order to publish an app to the Firefox Marketplace. NOTE: You can scan your WEBAPP manifest file for correct formatting and appropriate values with the Mozilla Web App Validator.