This is a basic phone stand I designed in Tinkercad. I used it as part of a larger project with some designs from others I found here on Thingiverse for a Star Wars Father's Day Project.

If you'd like to modify, remix the original STL file's individual pieces, the link to the design in Tinkercad is here:
https://www.tinkercad.com/things/f5il1K8PuiI

The flat, back part could likely be shortened, depending on what you'll be using it for. Could also increase or decrease the infill to make it stronger or weaker. You could also remove the recessed square on the front. In my case I printed a Mandalorian logo and placed it in the square.

I used a raft and supports when printing. The raft may not be required at all, depending on your printer.