These tiny quadcopters weigh about 20g in total and unfortunately don't provide enough lift to carry a smartphone - but you get the idea.
putting 8 motors (octacopter) on a frame made from straws should give enoug lift for about 15g payload. the maiden flight:
backside of an old iphone that was lying around.
It will for sure break the fall but it won't fly. (20g)
Maybe this is not the rout to go - but how could would it be if you could just place your phone in mid air ...