Phone holder for easy edge swiping, customizable

Yet another phone holder/stand. This one had the following design requirements:

• The phone edges (in particular the bottom) remain free, to allow easy use of the Android gestures for going back/home by swiping in from the edge of the screen. This grips the phone at the screen corners instead.
• Stable, with a quadratic rather than triangular base, to avoid tilting when you tap the screen too hard.
• Low filament consumption.
• Nothing too fancy like hinges, collapsible hinges, your favourite 3D figurine... :)

The disadvantage of the design is that both phone thickness and phone width must match the phone - solved with a customizable FreeCAD file. For those who do not want to edit parameters themselves, I've generated a number of common sizes/thicknesses. If your size is missing, also feel free to add a comment.