This is a model based on bernabap's GameClip. It holds a Samsung Galaxy S6 with a thin TPU-case (72mm wide, 8mm thick) to the PS3 controller (Dualshock 3). I placed the phone over the controller for a better center of gravity so it takes less effort to hold.
Expert Cura users only: I also included two volumes for more detailed infill and excluding support. For this you need the per-model-settings and mesh features in Cura v3.1.0+. You can use them to remove all supports where you most certainly don't need them (anti overhang mesh) and increase the infill at the weak spot around the Home Button (infill mesh; I recommend overall infill of ~25% with 2 walls and 90% infill for the infill mesh). Just merge the objects when you applied all settings.
This is licensed under the GNU GPL v2. There is no warranty.