My old A-level Computing final project from maaaaaaaany years ago. Revived from ancient backups!
To run it:
cd virtual-puzzle/
javac src/*.java
java -cp src/ VirtualPuzzleApp
First thing to do once the app has loaded is add a user, then select “Manage Puzzles”. Add a puzzle, you’ll need an image file in any of the common formats (JPG, PNG etc). Choose the number of pieces depending how hard you want to make it. Then go back and select “Do a Puzzle”, choose it, and off you go.
For more info see the project page on my site.