Yes, make sure you don’t hold the learn button when you program GarageDoorBuddy to your opener. Holding the learn button will erase the opener’s existing remotes.
GarageDoorBuddy supports up to two garage door openers. Pairing is only required for the first phone. Any subsequent phone just needs to connect to your home WIFI network, then input the same app password as the first phone to start using the app. No need to pair again.