Oops, I copied the downloaded file to the phone. I re-installed the whole thing and now it works. Will I have to pay for it AGAIN when the 21 days are up?
To (re)install BirdieSync on the mobile device you could also have copied on the mobile device and executed the appropriate cab file located in the "Installation" BirdieSync sub-directory. But the most simple solution is simply to fully reinstall BirdieSync as you did.
If you've already upgraded your license for BirdieSync 2.0, your license is still valid. If you are displayed a trial period with a number of remaining days in the license window, that may mean that you have to enter your license again.