Google Play Makes it Easier to Test Android Apps
You can try some betas with a couple of taps.

It's not too hard to beta test an Android app, but the process still tends to involve jumping through a few hoops. You might need to visit the developer's website, for instance, or join a community. Thankfully, it's about to get downright trivial in the near future: Google is rolling out a Play Store update that lets you join (or leave) Android betas right from the regular app's listing. Certain tests may ask you to sign up for a Google+ community first, but you won't have to go scrounging for a beta-specific app entry or download an installer from a website.

The updated store will also let you know when you're using a beta-only app (that is, there has never been a finished release). And you're not writing regular reviews anymore -- instead, you're leaving private feedback for the developer. It'll sadly take some time for the Google Play update to automatically reach your device, but Android Police is offering an install file if you just can't wait to experiment with unfinished code.