Pretty much what Beaker said, I had my Nicolai ebike supplied with the Powunity fitted, so I can’t comment on the fitting.
It was a proper PITA to get the app to connect and complete the initial set up, but you only need to do that once, after that there’s no connection needed between your phone and the tracker, it’s all handled over it’s own data connection.
The map does sometimes lag a little, but it’s impressively fast in notifying when the bike is moved, often takes less than a metre.
I’ll definitely be renewing at the end of the year, and also fitting another to my wife’s Liv ebike.
Well worth it given the somewhat insane prices for these things!