Currently, the Canvas Teacher app for Android is a brilliant way of quickly recording audio feedback on an assignment and posting it to individual students. In fact, I've personally found it much quicker and easier to use than the Canvas web interface (though the HTML5 upgrade has improved things a bit there, so thanks!)
However, the app isn't quite as useful for leaving video comments. It appears to be hardcoded to only use the front-facing "selfie" camera. This might be helpful for instructors who want to make their comments a little more lively and personable, but I would prefer to be able to point my device at the students' work and point out what I'm referring to as I talk about it. I can just about manage this by turning my phone around, but then I can't be certain whether whatever I'm intending to capture is actually in-frame or not.
It would be helpful if video comments could have a toggle switch enabling the user to decide whether to record using the front-facing or the rear-facing cameras.