Re: Sounds familiar
Indeed. In fact Bluetooth would only work if you were nearby the lock, in which case just give them the key.
I have a smartlock on my house, it's ZWave controlled. I can open the door remotely if needed, such as a locked out child who forgot their key.
I don't believe it to be unhackable, but it's certainly more secure than the cylinder locks that are installed by default. Can't snap the lock if there's nothing to snap. It would take a lot of knowledge of how the system works to gain entry and to be quite honest in that time someone will have probably just thrown a brick through the window, or used a blowtorch on the UPVC, or one of the other attack methods that's much easier than sitting there with a laptop.