Move a rect on a (fake) grid.
new Gritter(document.querySelector('#zeichenblock1'));
new Gritter(document.querySelector('#zeichenblock2'), {debug: true, color: "#008000", speed: 25});
see: gritter.js
new Gritter(document.querySelector('#zeichenblock1'));
new Gritter(document.querySelector('#zeichenblock2'), {debug: true, color: "#008000", speed: 25});
see: gritter.js