easy, peasy, lemon squeezy !
Foldable phone stand, print in place, no supports required.
Print time just a bit more than a hour.
It's based on an old design, but now enhanced as print in place.
If you use the STL and slice it from the scratch, dont't forget to divide it into single objects to avoid printing it in a single part (take a look at screenshot of PrusaSlicer).
If it dosn't fit for your mobile device, leave a comment, I will adjust my design.
/*edit*/
Fix an issue with the axis. It fits now better in folded condition.
Files marked with -v2 in filename
The author hasn't provided the model origin yet.