Is it possible to connect "Flipper Authenticator" and "Bluetooth Remote" apps to the same device via Bluetooth?

Yes, it is possible.

However it is necessary to keep in mind that "Flipper Authenticator" and "Bluetooth Remote" apps are using different Bluetooth keys storage. "Flipper Authenticator" app stores Bluetooth keys in /ext/authenticator/.bt_hid.keys while "Bluetooth Remote" app stores them in /ext/app_data/hid_app/.bt_hid.keys. This means that if you are not running Xtreme firmware or Unleashed firmware and you pair your Flipper to another device via "Bluetooth Remote" app, you will not be able to connect or pair "Flipper Authenticator" app to the same device, and vice versa.

Fortunately, there is a workaround for this problem. Once you paired Flipper to another device it is just necessary to copy Bluetooth keys to another storage to let another app access that keys.

Example #1: If you paired Flipper to another device via "Bluetooth Remote" app you need to copy /ext/app_data/hid_app/.bt_hid.keys file to /ext/authenticator/.bt_hid.keys. This will allow "Flipper Authenticator" app connect to another device automatically using existing key and as a result both apps will work just fine.

Example #2: If you paired Flipper to another device via "Flipper Authenticator" app you need to copy /ext/authenticator/.bt_hid.keys file to /ext/app_data/hid_app/.bt_hid.keys. This will allow "Bluetooth Remote" app connect to another device automatically using existing key and as a result both apps will work just fine.