Popp POPE010101 TRV

I am due to receive my first TRV tomorrow and have been reading through the forums in preparation. I couldn’t find a designated thread for this specific device so thought it’s worthwhile making one to aggregate what I’ve found.

It seems there are a variety of device handlers:

It also seems there is a few options for apps:

I’d be very grateful for opinions on what works best out of these options. Also, are there free apps available?