We have used this product on several high-profile iOS and Android applications, after using TestFlight for a couple of years; when TestFlight was acquired, Android support was deprecated. Managing two alpha/beta distribution solutions is cumbersome -- the Google Play service is prone to accidental mistakes in terms of release by inexperienced clients, and the TestFlight process is less streamlined for iOS distribution than the latest using Fabric (Crashlytics, Beta, Answer stack). It is simple, free, and platform agnostic -- what more could you hope for?