Carbide Create and Macromedia Freehand are the major stumbling blocks. The former isn't available for the iPad, the latter predates it, and I find the nearest

Carbide Create and Macromedia Freehand are the major stumbling blocks. The former isn't available for the iPad, the latter predates it, and I find the nearest analogue, Serif's Affinity Designer not quite right. I also like having access to a file system, and the ability to run arbitrary opensource tools such as OpenSCAD and OpenSCAD Graph Editor and RapCAD.