The free mobile app testing service has moved into beta for Android programs.
Until recently, TestFlight was a service that simplified testing of iOS-only applications. After installing its SDK, it is relatively easy to collect the codes of test devices and send working builds to testers without delay. Plus, it automatically monitors the actions of testers in your application, allows you to ask them questions directly in the game, saves logs and information about crashes, and so on. More details about this here.
So, now all the functionality of the service is available in a closed beta version and for those who develop for Android. You can register for testing here. By the way, TestFlight services are used by companies such as Halfbrick and Disney, among others.