Easy 3D design application

I got a great new 3D printer (the award-winning Original Prusa i3) and I’ve been using it to print useful things for around the house. The 3D design program I use is the free, web-based Tinkercad. It’s easy to get up-to-speed by watching a couple of brief introductory videos. I’m going to design a plastic ukulele with it. — MF