Since I like to browse on my mobile phone when lying on the back on my sofa, I figured why not make a 3D thingy to allow me to do just that.
So in other words with this thing, it is possible to hold a mobile phone with a flip cover that is flipped to the back with a steel hook (Hosmer Mod. 5) so that the phone is stable due to being held by the cover, so that the phone does not get scratched and does not fall off. In particular, this is practical for reading stuff on the screen while lying on the back on the sofa. It also has a hole where a screw or nail can be used to "fix" it to the hook; not that it falls off without it.
Buy directly (as 3D-printed shape / item):
Get STL-file for further play around:
This shows how the 3D shape presses against the phone. It makes sense to have a plastic (and not a metal) thingy for that reason.