Instructions
Click on the link you received in email.
Once you click on the email you will be redirected to a page similar to this.
Click on JOIN THE PROGRAM button. Note: If you do not see this button make sure you’re logged in with the same gmail account you provided to Trufla to access the beta version of the app.
You will see a page similar to this indicating that you have successfully joined the program.
Click on the link within this page which says download it on Google Play.
It will redirect you to Google Play store for you to download the Internal Testing version of the app. Click Install and wola you have the Testing version of the app installed on your phone.