Tinkercad is a free-of-charge, online 3D modeling program that runs in a web browser. Since it became available in 2011 it has become a popular platform for creating models for 3D printing as well as an entry-level introduction to constructive solid geometry in schools.
I was having a hard time figuring how to get my maker project coded, spent half an hour on the app and my code was working. Many tutorials for beginners and those who have been away from the game.