Product review (3 stars): Really great idea, but has some issues that I don't have time to deal with
I'm not having perfect luck with the app or the Bluetooth connection though it does work most of the time. I think that a digital hygrometer (you can find them for under $20 on Amazon) that you can just read is better if you're in the same location as your guitars, but this is a great idea if you're way from home often and if you have a less-than-perfect storage environment for your acoustic guitars. Of course, if I'm not around (if I'm away for a few days, for example) there's not much I can do to correct a problem anyway, but it would still be nice to know what's happening at home.

The problem that I have is that my digital hygrometer and this D'Addario device don't agree that often and so I have to decide which one is accurate. How? Also, like I said, the Bluetooth is buggy and as others have noted, the app is difficult to update. I like the concept of this and trust D'Addario, but I think this needs more work.

I really like the concept of this product though and I hope that the app and functions get refined a bit. I'll keep looking for software updates.