I have one of these, it is terrible I hate to say. I haven’t found a better alternative.
I bought 2 and planned to give one to family member but I don’t think I want to put them through the frustration.
It is amazing how poorly it works with the app. I mean this is whole basis of the company yet it performs like a alpha version of Kickstarter product. Don’t know if it is the hardware or the software but it has never worked for more than a few days without having to re-pair or usually do a full reset of the mug. Trying to update the firmware was a nightmare and required me to dig up an old tablet because it wouldn’t work on a current android. They claim to have fixed this (support took over 1 week for a reply to my email about the issue) but nothing else in the app has improved so not sure I believe them .
I have 3 Ember mugs (2 10oz and 1 6oz) and absolutely love them! No issues, and they all keep our coffee at the perfect temperature for at least an hour. This is about the time it takes me to enjoy one to two cups of coffee each morning.