soap dish

This is an absolute life-saver for any prison inmate: a soap-holder.
*badam tsssh*

It's meant to use 3 suction cups ( https://bit.ly/2Wpif3P ) which can be attached in a corner of your shower.

edit: I uploaded a 4-suction-cups-version since the previous one tends to creep after some time. This one is better. I'll upload a picture someday. Maybe.

editedit: This wasn't the solution. Turned out that the wall joint in the corner is a bit rough and therefore de-vacuumed the suction cups over time. So I moved those cups away from the corner and changed overall geometry a little... because of reasons.