How to use: pick a color, click or drag on the grid to paint (right-click erases). Use
+ Frame to add another step of the animation — Duplicate is usually the fastest way to
start the next one. Set how long each frame shows, hit Play to preview the loop, then
Save / Export to download a file — send that file back so it can be dropped into
assets/sprites/. Use Select to drag out a box around some pixels, then the
arrow keys to shift them up/down/left/right.