You did everything you could do to ensure the quality and performance of your app. Now it is time to ship your app to your beta users to see what they think of it.
Before shipping your app, you should have a look at Crashlytics first. You can find it at https://try.crashlytics.com.
Crashlytics can provide you with real-time crash reporting information not only during your beta tests, but also after releasing your app on the Play Store. Sooner or later, your app runs on a device that you have not tested your app on and it crashes on it. Crashlytics can help you find the cause for this.
Just download their SDK, add a few lines of code to your app, and you are good to go.
Distribute your app and get it tested before ...