I wanted to use thing:719230 for my smartphone - and had the idea to combine it with the universal tripod mount (thing:46378), which I printed a while ago.

The first try, with the mount right in the middle, showed that even an iPhone5 is a bit to big for the rig.
So I changed my design an moved the mount to the front, constructing a foot, making the rig selfstanding again. Now the gap between the phone and the handle is a bit wider. It would be a good idea to extend the top and bottom bar a bit more - on my CTC annother 1.5 cm would be possible.

The biggest advantage - besides the good grip - of such a rig is the possibility to mount accessory, as an extra light or an external microphone. Therefor I added an quarter inch thread to the top.

UPDATE 2020: I added extended bars, 25 cm wide instead of 20 cm. So the rig is more suitable for bigger phones. I printed them diagonally on my Ender-4 (22 x 22 cm printer bed). The first two pictures show the new extended version with an iPhone6 in a big case.

My mount for a bluetooth remote: https://www.thingiverse.com/thing:4178356

Print one of each except the grip which you need two times.
Print the grips and the bottomslot with support.

Uses
4x M8x50 cap head bolts and nylon nuts for the rig itself
4x 4-40 x 1/2 Socket Head Cap Screw for the universal mount
1x 2.5" x 1/4" OD Spring for the universal mount

If you want to mount accessories you have to get an 1/4 inch to 1/4 inch adapter (for tripods etc.), screw it in (use pliers, the thread might be tight) and add an hotshoe adapter.

For further instructions look them up here:
http://www.thingiverse.com/thing:719230
http://www.thingiverse.com/thing:46378/#instructions