[blakerson]

I had this in my last apartment in Tokyo.

In Japan, water is commonly heated by gas-powered flash heaters. In that apartment, the heater was controlled digitally and there were up/down buttons that would change the temperature by 1 degree Celsius.

It would remember the most recent setting between uses, so all I had to do was remember my favorite number, ensure it was set to that number upon start, and hop in.

It was simpler in function than a Nest and much less pretty, but it was functional and got me the water temperature I wanted.