
Description: Amazon Underground is an app store by Amazon that offers premium apps for free with limited advertising. It's available for Android devices only.
Type: Open Source Test Automation Framework
Founded: 2011
Primary Use: Mobile app testing automation
Supported Platforms: iOS, Android, Windows

Description: AppsGoneFree is a website and mobile app that provides a curated list of paid apps that are currently free or on sale in the iOS App Store. It aims to save users money by notifying them when popular apps go free or on sale for a limited time.
Type: Cloud-based Test Automation Platform
Founded: 2015
Primary Use: Web, mobile, and API testing
Supported Platforms: Web, iOS, Android, API