Just to make sure we are talking about the same thing
Step by step
1) Make sure you android phone is linked to the email you gave me. Open 'settings' app, find 'Accounts' screen and check google account
2) Follow the link
https://play.google.com/apps/testing/com.leaf500.filmlog and make sure you log in under the same account in the browser
3) It will ask you if you agree to become a tester, bla bla bla.
4) Click "download it on Google PLay"
5) On the app page click 'install' and choose your phone from the list
You only do this once, after that it will get updates as a normal application