Are there concerns that unpatched Android devices could be vulnerable to the Bluetooth bug discovered in February this year?
https://www.welivesecurity.com/2020/02/07/google-critical-an...
https://www.welivesecurity.com/2020/02/07/google-critical-an...
As for how it relates to the app, I don't think it matters much. I'd imagine most people already have bluetooth enabled, so using this app or not won't change their vulnerability status.
[1] https://insinuator.net/2020/04/cve-2020-0022-an-android-8-0-...