It would be wonderful in the iOS app had a draw feature. It also makes perfect sense since it is easier to draw on a tablet/phone than using a mouse/trackpad on a computer. Please make this happen!!
Agreed, if using (e.g.) an iPad with an Apple pencil, it should be possible to use it as an annotation layer for an overlay.
Also, not sure if the APIs exist to be able to do this, but it would be nice to be able to use the mobile app to send … instead of the video camera output from the mobile device’s camera … a stream capture of the mobile device’s screen.