I am looking for modern science fiction films (1995-today) that use aspects of the relativity theory. Interstellar is already in my list. I am thankful for every recommendation.

You took the one that immediately leaps to mind. Sci-fi conveniently ignores relativity most of the time. (The only other one I can think of that even pays lip service to it is outside of your time-line, being Planet of the Apes, and they credit the idea to a fictional character)

Star Trek's warp drive warps space to allow superluminal speeds, if that is the kind of thing you are looking for.

 

I remember an episode of Star Gate where a team is caught near a black hole and the extreme time dilatation causes them to apparently freeze.