Google has launched a new process for beta testing the Google App via the Play Store. The Google App is the software that powers several functions on an Android device like the Now Launcher, Google Now cards, Now On Tap, and some other functions. In the past users had to go through a G+ community, but now users can just visit a web page setup by Google in order to sign-up. Once a user does so, they will be directed to the Play Store where their app will get the update to the beta version.
Reports from those who have already signed up indicate the current beta build is version 5.4, which has already been out in the wild as an apk. Whenever the next update to the beta build takes place, users may have to poke around to figure out what has changed as Google typically does not post detailed changelogs.
If you are interested in trying out the Google App beta, hit the source link below. Just remember, as Google notes, a beta version may be unstable and contain some bugs.