Tools      R rod · D drop · C comb · W swirl
Inks       1 – 8
Size       [ smaller · ] larger
Undo/redo  Z / Y  (also ⌘Z / ⇧⌘Z)
History    ← / →  tick · ⇧← / ⇧→  ×10 · Home / End
New bath   N
Explore    E  ring of nearby variations · tap one to move there,
              tap the centre (or Esc) to return
Save PNG   S  (also ⌘S)
Debug      B · Help  ?

Comb spacing  pinch with two fingers (or trackpad pinch)
Bars move by their stippled handles (or the title).
Palette    P  random harmonious hues (saturation slider is kept)
Tap a selected swatch again to edit its colour.