I would love to introduce SharePlay in my own app without having to use Facetime.
SharePlay is built on FaceTime so it is required for your users to be using FaceTime to participate in a SharePlay experience together.
When the user is not in a FaceTime call your application will not be eligible for a GroupSession so the return from GroupActivity.prepareForActivation()
will be activationDisabled
and the GroupStateObserver.isEligibleForGroupSession
will be false