Bug2: Hm. Tried it a second time, just before answering. It works. So, please ignore this :-)
the pipette-tool only selects colors already drawn with. Would be useful to select any color on screen.
Hi, nice tool!
On my Mac using nwjs.app, it steals the keys, when open. For instance, the space key is trapped.
The fill-tool fills the whole image, when clicked in the transparent area.