@FediTips Nice list.
Probably you could add #Freitagstexterei

On friday a picture is published by the last winner, where other user can post a story about with a maximum length of 500 characters.
The poster of the picture chooses the best story and assign the honor of posting the next picture to the winner.

Maybe a shorter description:
A weekly contest with maximal 500 characters fitting to a posted picture on friday.