ShapeCalc is an app intending to unify geometry calculations, by having all shapes in one place. I first published ShapeCalc when I was 12, March 2015. Back then, it only had one shape: the right triangle. Since, it has evolved to 18, including 3D shapes, and even has some easter eggs.
Since publishing, ShapeCalc has garnered over 2,500 downloads in more than 80 countries. It is no longer on the app store due to costs, but will always live on.