I'm using the iTunes API too lookup some info about apps. I'm trying to figure out if it's possible to find out if the app has an Apple Watch companinion app or not via this API.
https://itunes.apple.com/lookup?id=705350439
This app has a text on it on the store page that says "Offers Apple Watch App for iPhone" and also some Apple Watch screenshots. But they doesn't seem to show up in the API.