I was about to buy this sous-vide device because it might be fun to play with, and for $20, who cares if it works out.
But I read the reviews for a minute, and the reviews say you need a subscription app to get full functionality from the unit. Apparently, it has limited functionality that you can use for free with just bluetooth from your phone. Some reviewers report that the unit is quite usable with just bluetooth, but other reviewers report that the bluetooth is insufficient, or just won't work.
All of this was enough for me not to buy it. I would spend $20 to play with a cooking device that I might not like, or that might not work for recipes I want. But I am not willing to start the cooking project with a phones, apps, and subscriptions project. I can do all that stuff, but it sucks the fun out of things for me.
So obviously, I have not tried this unit, and I will be interested to hear results from anyone who does. But I just wanted to put this note, because for $20 I almost clicked "buy now" without reading anything, and I am glad I didn't.