Been using the Watch for Tesla app for a couple of weeks and it’s great for the basic functions. Think it was $8 or so.
It's great. Started using it last summer and it was very nice to turn on the AC via the watch while walking back to the car with an arms load of stuff. Nice cool car on a hot day after the beach.
Also works great walking back to the car and popping open the trunk to help you find your Model Y in a sea of cars.
The developer keeps updating it too and I just recently found out you can reorder and reorganize the buttons. I have Climate, Frunk and Trunk on my first screen so no need to swipe left to get the trunk open. I think the app default is Climate, Frunk and Lock.