FYI, theres a new app out to manage this, seems good. Heres the email they sent me:
Hello, I saw your post on reddit and had a look at Shifty Habits's Play Store page — that's where I found your contact email. I'm building TestCircle, a free mutual testing app to make closed testing easier for the community.
The idea is simple: instead of scrolling through various Reddit posts, chasing people individually, joining dozens of separate groups, everyone joins the same single Google Group, then installs and tests each other's apps over 14 days in 5 organised phases. All testing feedback is centralized in one place inside the TestCircle app.
It just takes a few minutes with 3 simple steps to get started:
It's completely free, and I hope it can help you get more testers easily and then successfully get your app approved for Production after the 14-day cycle! And of course if you have any feedback or suggestions on how to improve the concept or the TestCircle app itself, I would greatly appreciate it.
I wish you the best of luck with your app testing!
Antoine from TestCircle