iOS - How to show hints for gestures for iOS app?
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I have seen some apps where when you launch them for the first time after downloading (e.g. Chrome app on iPhone), it shows you a list of animated gestures on the screen, kind of giving you a tour of the app.

How do I build one something like that? And how does the app know to launch only for the first time after download and not since then? For the second question, I am guessing a "shown=TRUE" value can be saved inside a PList file and checking the value each time when the app finished launching. But I am more curious about the mechanism involved in creating a guided app tour.