1. the feet can be moved individually, but they do not lock in place, so there are no intermediate steps, only open and close. Uneven surfaces can only be compensated for to a very limited extent. In addition, the feet are quite thin and only 10 cm long, so the whole thing is a rather wobbly affair and rather top-heavy, probably also susceptible to wind. At least you can unscrew the feet if they get in the way.
The shutter release has one button for Android and one for iPhone. No app is needed for the iPhone. After pairing, one press of the button activates the camera shutter if the camera app is open AND in the foreground. Otherwise, pressing the button causes a volume increase on the iPhone.