>>12426351Geometer's sketchpad is pretty neat. I used it in highschool to do some geometric constructions in math class. There's also this app for Android called Euclidea. It's a game where you try to make geometric constructions, if I remember correctly there's a free sketch mode where you can fuck around and do what you want. Basically an app form of geometers sketchpad. Not sure if there's an iOS version.
