Hello @elopez5
Thanks for posting this in the global Canvas Community!
Currently, the iOS app for students does not allow them to use the pinch gestures for zooming in and out on certain content in Canvas. I am not sure why this is the case, honestly. Seems like a limitation or something? I assume this might be due to the way the app displays specific content in a given Canvas course.
I believe that they should be able to Zoom in and out on items like files that you have added to the course. The reason for that is due to the fact that the Canvas doc viewer is actually rendering it within the app.
Hopefully this helps!
-Colton