Back at Google I/O in May, Google announced a few new changes to the Google Play Store. Some of which are beginning to roll out now. The biggest change was in regards to beta and alpha apps. A few years ago, Google added the ability for developers to test their beta versions of their apps through the Google Play Store, by having a group of users opt in for beta testing - through either a Google Group or Google+ Community. In 2016, Google decided to take that a bit further and is making it easier to find these beta apps as well as apps that are unreleased and still in development. One of the changes is bringing a section to Google Play that shows unreleased apps that you can check out, and that appears to be available for everyone today.
On the 'Apps & Games' home page of the Google Play Store, you'll see in the carousel of banners that there is a new banner for 'Early Access Apps', tap on that and you'll be taken to a list of apps that are currently unreleased. There you'll see apps like & Ava, Wiz - Your Tech, Zypotonite - Private, Operator: Shop, Readfeed and many others. There's also a bunch of games that are under development like Lego Go Build, Titan Brawl, TyrAnt, Nemesis: Air Combat, Castle Cats, Up & Up and many more.
That's not all that's new with this feature, if you jump into "My Apps & Games" you'll now see a third tab named "Beta". This will show you all of the beta apps you have installed on that device. If you want to leave the beta test, just tap on the app, and scroll to the bottom of the page and tap on "Leave".
These features began rolling out to some users last month, but now it appears to be available for everyone on Google Play. If you aren't seeing it, force stopping the app in settings may trigger the changes. Now you'll be able to check out some new apps and games before they are released to the public, which makes for a pretty sweet feature, to say the least.