Add an atomTap an element in the bottom bar, then tap the canvas — or drag it up. It stays selected so you can place several.
Periodic tableTap it for any element, then tap the canvas to place.
BondTap one atom, then another. Tap the bond to cycle single → double → triple → none. The link chip returns to this default mode from any tool.
Lone pairTap the : chip, then tap an atom — each tap cycles 1 → 2 → 3 → 4 → none, like tapping a bond. Double-tap an atom to clear them all at once.
Move / ReplaceDrag an atom to move it. Drop it on another atom — or place a new element on top — to replace.
DeleteTap the eraser chip, then tap atoms or bonds — or long-press an atom to remove it and its bonds.
Quick menuPress and hold any empty spot on the canvas for a mini palette: your two most recent elements, lone pair, bond mode, and the eraser. Slide onto a tool and release, or tap it; tap anywhere else to dismiss.
ChargeUse − / + at the top right to set the ion's overall charge.
NavigateDrag empty space to pan, pinch to zoom, double-tap to zoom in/out. Fit recenters everything.
CheckVerifies octets, electron count, and whether formal charges could be lowered.
Icon barUndo · clear the canvas (trash) · show formal charges (±) · hide circles for a textbook look (dashed circle) · copy a PNG (clipboard) · save structures or share a code (disk).
