Product review (4 stars): Device works, app needs improvement
I'm using this on a GE GeoSprings 50gal hybrid water heater.

Instructions are fairly simple but the associated iOS app for this is awful!
Took a few tries to get through the setup process in the app due to crashing and menus not appearing as they should.
After setup, the app seems to be ok...not great, but OK.

This device is now compatible with the Amazon Echo and I do have mine setup to work together.  Not sure how useful this will actually be but is kind of neat to be able to ask Alexa for my water heater status.