[editor's note: copied from comment on main article]
There are a lot of jigsaw programs out there, but none of them (as far as I know) allow you to
design the pieces as rectangles.
Why? you might ask.
Well, for instance if you have a picture (say jpeg) of countries and their capitals and the program cuts
this picture into rectangles - you have a ready-made drag and drop quiz.
As each rectangle (country) is matched with its matching rectangle (capital) then the two rectangles merge as one . . and this continues for the remaining countries until the picture is complete.
The BIG ADVANTAGE of this is that ANY PICTURE of lists or pictures can be used to aid learning.
The only problem that I can see, is that you need to indicate to the program how large each rectangle must be ( as you can have any number of fonts for your lists or picture sizes).
I hope you can give this idea some consideration and almost certainly suggest your own improvements.
I do feel that this program would be incredibly helpful, especially for children.