This is a parametric design for a socket-like stand for a tablet or similar device. It consists of a rectangular base, the socket itself that is intended to hold the device by gravity and friction. There is an optional extra post on either or both sides of the socket (allowing you to clip something onto it), optional grooves/ridges on the back part of the base (in case you want to use some kind of supporting brace), and optional mounting holes in the base. Optional raised lips can be put on any or all sides of the base (for example, to keep your pencil from rolling onto the floor). As a separate piece, there is a clip-on brace. The defaults for everything are convenient for a Raspberry Pi 3B+ bolted to a touchscreen that I needed to mount standing up.

Why use friction fitting for a tablet instead of the more typical resting-on-a-ramp design? One of my use cases is for inside a car. I wanted it held reasonably firmly in place yet be removable if I needed to do a firmware upgrade or whatever.

There are extensive explanatory comments in the OpenSCAD file. One of the render images and photos are the stand for a Raspberry Pi mounted on a 7 inch tablet and enclosed in a 3D-printed case. It's also what most of the default values in the OpenSCAD file produce. You are unlikely to need exactly that thing, but I thought a concrete example might help visualize what this thing is. I also provided the STL for that so you can view it in 3D here. (The thing I printed and used is slightly different from the rendered image, but the basics are the same.) Another rendered image and STL file are for an Amazon Fire 8 tablet.

For both of the prints you see in the photos, I used PLA/PLA+ and later re-did it with PETG (because it will live in a car). With the thicknesses I used, 5% infill seems pretty sturdy (though I used 40% for the brace because it didn't change the print time much). I used 0.20 layer thickness.