I'm building Sticker messaging application. When I try to run the app on iPhone SE simulator with iOS 10 it throws a window to select application through which Sticker app extension should run.
However, in this list there is Siri, Today and Watch app only. There is no Message app. This was working when tested on last week.
Due to this Sticker messaging app extension cannot be tested on iMessage app on simulator.
Why this is happening?
This is probably just a bug in the beta. I've found that this happens with the iPhone SE simulator but the iPhone 6S simulator works fine.
To solve this, if you run the app with one of the other options, the option to launch the Messages app should be available the next time you run the application. So run the app in the simulator, select Siri, and open the Messages app manually. Next time you run the application the option for Messages should be available.
Also you aren't running the latest Xcode beta. The latest version is Xcode 8 beta 4.