This plugin superimposes the current shown glyph as a rotated copy of it self depending on the value you set in the transformation rotation field. It can be pretty helpful when you are working on symmetric characters, it can help you to balance letters.
“Speed Punk is a learning tool. It teaches you to better understand the nature of Bézier curves and their curvature, the technical basis of digital type design.” Speed Punk shows the user in a really visual way, how the curve works and its behavior when you play with the handlers, so you can see easily problems and discontinuous curves if graphic shows a jump. Now you can check how smooth are your curves.