In the iOS 12 Shortcuts app, I'd like to build a shortcut that opens a specific app. This app doesn't have any specific integration with Shortcuts, but it's sufficient to just have the system open the app. So I added an "Open App" action to the end of my workflow — but the app I want to open does not appear in the list of choices for the Open App action.
I noticed that a small fraction of apps on my phone are missing from the Open App list. It seems pretty random: Apple Pages is missing but Keynote is not, some but not all games are missing, etc.
Is there some reason that I cannot open certain apps via Shortcuts?