The Element buttons (C, H, N, O, S) change the selected atom or atoms into the element tapped. If the tapped Element button is a heteroatom, the appropriate attached hydrogen atoms will be displayed.
Tap the Table button to access the Periodic Table of the elements.
The Sprout button adds one carbon atom to each of the selected atoms.
The Formal Charge buttons change the formal charge of each selected atom. Hydrogen atoms shown will be adjusted for nitrogen, oxygen, and sulphur atoms to match the formal charge state of the atom. For the best result, draw the neutral structure first, then add formal charges.
The Single, Double and Triple bond buttons change the bond type of each of the selected bonds. With any number of bonds selected the bond buttons change the bond type. With any number of atoms selected, the bond buttons will create a new bond if one did not previously exist. The exception is when two atoms are selected and the Single bond button is tapped, in which case a single bond is formed between the two atoms. The Triple bond will change the orientation of a terminal bond to have the correct linear geometry.
The Up and Down Wedge bond buttons change each of the selected bonds to up or down wedge bonds respectively. If the button is tapped a second time, or if the wedge button is tapped with a wedge bond selected, the direction of the wedge is reversed.