Today, while I was watching the following video:

Chemistry -> Electronic structure of atoms -> Quantum numbers and orbitals -> Heisenberg uncertainty principle

just before the 8 1/2 minute mark, a correction bubble popped up on the screen. This is something I've observed in the website version of Khan Academy but not in the app versions. Thank you, Khan Academy, for adding this feature to both the iOS and Android versions of Khan Academy.

I had actually watched this video before from a Physics playlist, and the bubble was not present then.