GROWLr now allows users to migrate their own profiles. Before trying to migrate, make sure you go into your existing profile settings, and set your email and password options in the fields provided.
Once you have done this, or is you had already entered your information, you are ready to migrate.
Download GROWLr onto your new device, and tap to open.
Choose Log In, then enter your email and password combo in the spaces provided and tap OK.
You have now moved your account to the new device.
IF YOU ARE GOING TO RESTORE YOUR GROWLr APPLICATION TO YOUR NEW DEVICE FROM iCLOUD OR iTUNES:
Once you have restored your information onto your new device, open GROWLr.
Go to your profile settings, and scroll down too and tap Login.
Enter your email and password. You must do this to completely migrate your existing profile to your new device.