I wasn't able to find a simple design for something that I could sit my phone on while I'm in the shower. I usually like to listen to music while I am in there so a decent holder was what I wanted. I used my little knowledge of Fusion360 to make this little shelf to attach to the wall in my shower using two suction cups with hooks.

I first printed one at the 100% scale but my IPhone 12 Pro has a case on it that was a bit thicker than I thought. So I printed one more at 120% and its just what I was looking for!