Early Access - Google Play
The Early Access program in Google Play, which opened up in early June, was initially announced at Google I/O as a way to get indie developers access to a wider test audience before launch. Today, Google is opening up access to the Early Access program to more developers.

The Early Access program launched with games and apps from 29 partners, and it’s been a roaring success in terms of adoption. Apps and games in the Early Access program have been downloaded more than a million times since it launched.

To access the Early Access section and check out upcoming titles, it’s pretty easy to do. Open Google Play on your phone and scroll the categories across until you see the Early Access button.
Google Play Early Access

If you’re devloping an app or game, or know a developer trying to get some testing done, you can have them apply to add their title to the Early Access program by registering their interest with Google through this form.

Source: Google.