Tado is great, and since 0.93 (or 0.92 if you had followed the special steps) it is possible to have them run locally through the homekit controller (NOT the Homekit component, they are different things, so you DON’T need an Apple device for this at all).
Works locally and via the cloud. Been using this since november, and they are great, easy to install and setup. Batteries last pretty long.