There is/will be no built in way to monetize apps.
If you want to sell apps, you have to set up your own infrastructure or use existing third-party solutions.
For Pebble there were several options.
One was selling a companion app. Without app on the phone, the app on the watch won't work.
Another was to create your own companion app, and you then can purchase the watch apps via that app.
A popular third party solution was KiezelPay. They basically do all the payment management for you (for a fee).
KiezelPay will also be available for the Ionic and personally I'm planning in using it, so that is something you could check out.
