To start testing the beta version of SCRUFF:

1. Open the mobile browser on your device.
2. Visit the SCRUFF App Testing page.
3. Tap Become a Tester in the lower right.
4. You'll receive an update to SCRUFF beta version via Google Play.

Once you've completed these steps, you'll be a beta tester of SCRUFF. 

To stop testing the beta version of SCRUFF:

1. Open the mobile browser on your device.
2. Visit the SCRUFF App Testing page.
3. Tap Leave the Program in the lower right.
4. Uninstall the test version.
5. Install the public version on Goole Play.

Once you've completed these steps, you'll no longer be a beta tester of SCRUFF.