Link to this puzzle: by game ID by random seed
The graphics and coding using Emscripten javascript are by Simon Tatham. At present
(2018) his puzzle website is at https://www.chiark.greenend.org.uk/~sgtatham/puzzles/ and worth a visit.
The original Java puzzle was devised by Paul Scott (http://www3.sympatico.ca/paulscott/).
You can record your moves by numbering the squares like this:
and if you really do give up here is my
solution in 17 moves.
16 15 11 10 9 10 6 2 3 4 8 7 6 7 3 2 1