I haven't developed an Apple Watch app yet.
I have an existing app for sale. Users of that app sometimes send me requests for functions using Apple Watch in the app by email.
Considering future maintenance, I would like to sell the Apple Watch app as a paid app.
However, I know that watch app support cannot be turned on/off by in-app purchases in existing apps.
Is there any way for the standalone Apple Watch app to communicate with my existing paid/free apps?