I wanted a nice looking stand that looked interesting when the phone wasn't in it... and was small. It needed to hold my phone in a horizontal position for viewing.

Original Design: (8-5mm STL file)
The slot in the feet holds a phone who's thickness (at the edges) is <8.5mm thick.
(8-5mm STL file). As previously noted, the design could easily be resized to hold a larger phone (see below).

Update:
I had a friend who wanted to use with his phone case... I modified the design to allow a 13mm thickness as well (13mm STL file)

Update (10-22-2016)
Added a 22mm wide variant STL for someone with a big phone case.

Update (10-15-2016)
I had wanted to learn OpenSCAD, so as a first project, I decided to re-create this design in OpenSCAD and make it available for the Customizer.

You can select your phone thickness (8mm to 15mm) and the base will accomodate by making the slot wider and adjusting the angle in which it sits to allow the back of your phone to lean against the backrest sphere.

Disclaimer - I haven't tried to print one from the OpenSCAD / Customizer. If you use the customizer and make one, please let me know how it works so I can try and improve it as required. Thanks.