I think there are two very different things you want. One is test our application on a great number of devices and Android version combinations. This is to make sure your app runs smoothly on all the environments you need. The other is a way to collect usage data, core dumps and physicians feedback.

The first thing can be accomplished with a device farm and automated tests. Xamarin Test Cloud ( http://xamarin.com/test-cloud ) allows you to to automated testing on about 600 devices. There are other providers but this is the one that I would use and trust the provider.

The second thing can be accomplished using many tools, even the ones you already use, e.g., trello or slack, for feedbacks. I have seen many companies go for beta releases on Google Play linked with private Google+ groups for beta testers.

For crash dumps and usage monitoring you can use Twitter Clashalytics ( http://try.crashlytics.com/ ) or other tools like:

* http://www.mobtest.com/
* http://ubertesters.com/
* http://hockeyapp.net/
* http://www.centercode.com/