I ran into exactly this. I ship a voice-input custom keyboard: the keyboard opens its containing app so the app can record audio, and after recording starts I would like to hand the user back to the app they were typing in. There is no supported way to do that last step. I have filed a request for a public API as FB24235692. To keep it as easy as possible for Apple to consider, I framed it as a privacy-preserving request: my app does not need to learn which app hosted the keyboard, it only needs a way to return the user to whoever initiated the launch — something like UIApplication.returnToOpeningApplication(completion:). No identity would be exposed to my app. If you are hitting the same wall, please file your own report and reference FB22247647 and/or FB24235692 so the duplicates are counted together.