TestApp.io - A platform that helps both mobile app developers and owners to easily share their apps with everyone to get feedback before reaching publicly to Google and App stores.
TestFlight - iOS beta testing on the fly.
TestFairy - Painless Beta Testing
Beta Family - 50,000 testers to test your app
Install On Air - Install On Air offers Testflight and Diawi Alternative for iOS and Android App. Distribute your application in less time with best platform for app distribution.
Visual Studio App Center - Continuous everything – build, test, deploy, engage, repeat