I made an application similar to this. but I haven’t tried yet. What I want to ask is, is there any problem in google synchronization after the purchase? Or does the watch face look like it wasn’t purchased?
well i am still having sync issues after purchases still shows me unpaid on watch. I tried few other developers tested some new faces, same result. But this is a good solution for free watchfaces 
I have been installing watchfaces from web version without issues since months that the only thing that has worked for me always 
So for paid watch faces, this app makes no sense. Thanks.
i updated this watchface yesterday. Strange thing is few i updated have missing install button. ,but this one still has the install for other devices button in playstore app.
This happened to me as well not sure about the reason, i am suspecting that when i updated one of my watch faces it changed to having install more options not sure though. Might worth a try.