If you made a widget for summon, I would definitely buy the app.
I use Remote App for Model S for my Apple Watch app and it's really good. On my iPhone, I use the native Tesla app which does the job even if it takes a few seconds longer to perform an action. However, both of these iOS apps lack Summon widget functionality. I can do Summon from the Remote S Model Apple Watch app but it's quite a few clicks as you have to launch the app from a complication, then scroll to a screen and then force touch and then select forward or reverse...