To access TheBrain 9 Android beta, you need to sign up to become a beta tester:
-After joining the G+ community, open the About Community tab, click the Beta Signup link, then click Become a Beta Tester.
-You will need to update your app. If there is no update on the Play Store, uninstall and reinstall.
-Open the app, (logout if you are logged in) and tap the menu button in the top right, then select "Go to Version 9".