For bluz specifically, we have apps already that provide that connection. But ultimately, you would probably want your own app, and you could base the connection part from ours as all our code is open source.
Yes, the app is another component that the product creator has to worry about developing. But for those use cases where the app makes it easier on the customer, it could be worth it. Again, not even bluz specific, I just think the concept is valid.
It's just another option I wanted to throw out there. With unlimited data plans in many people's pockets (at least here in the US) using that for devices that require interaction can be a valid model. Clearly it wouldn't work well for systems that need to be online 24/7, but that doesn't sound like your use case.