I recently found an elegant solution - Velcro. The seats on most airlines have a small patch of Velcro "hooks" (that's the rough side of Velcros) used for attaching a small headrest cover. In this Instructable I will show you how to mount your tablet using this small Velcro strip as a base.
Step 1: Materials
What you will need:
* 1 meter of Velcro (both sides - hooks and loops) with a sticky back
* a tablet
* cheap back cover for the tablet (optional)
Step 2: Preparing the Mount
* cut a 20cm hooks piece
* cut a 20cm loops piece
* remove the protectors from the sticky back and glue these two pieces together
Now we'll need two long vertical strips. Cut two 30cm (or longer) hooks strips, and attach the tip of these strips to the sides of the base piece. Do not remove the sticky back protectors. I suggest leaving some room on the sides of the mount piece for better grip. If you do it right, you will get something that looks like a PI symbol (Π).
You'll might want to take some extra Velcro with you, for final adjustments. Just make sure you cut everything before you go on the plane - bringing scissors on board is probably a bad idea.
Step 3: Preparing the Tablet
* the strip should be installed horizontally
* the strip should be wide enough to match the vertical strips of the mount itself. Use 20cm or more
* use two (or more) strips for better stability
Step 4: Mounting
1. Carefully remove the headrest cover of the seat in front of you
2. Attach the tablet mount to the Velcro on the top of the seat. The hooks side of the mount base should point up. The two vertical strips should be pointing you
3. Place the headrest cover so the other passenger won't suspect anything
4. attach the tablet to the vertical strips. Move up/down to adjust the height
Now for the tricky part - adjusting the viewing angle. On my tablet I have this small built-in leg that I use to push it away from the seat. If you don't have one (you probably don't...) you can either find a back cover that has one or just come up with a cool solution and post it here :)
Have a safe flight!
(P.S - Thank you Singapore Airlines for those photogenic seats!)