Take three barf bags from the airplane seats in front and to the sides of you, find the flexible thin metal piece and rip them off (hoping nobody will need to throw up mid-flight). Once this is done, use two for the bottom support and one for the top of the mount. Bending them properly, you can enjoy whatever smart phone media you have and make your flight a little less of a chore.
Original source: Phone Mount on Plane Seat
