Select Hairpin and tap in the score once to place the hairpin for the smallest appropriate duration. Tap and drag the hairpin to the right to extend it.
By default, a hairpin will be drawn as a crescendo; to change the hairpin to a diminuendo, drag the pen down. Drag the pen up to change it back to a crescendo. The hairpin won’t move vertically; only its state will change.
Simply drag the ends of the hairpin with the pen to extend them at any point. You can also drag up or down on them vertically to change their direction.
You can also draw a hairpin into your score.
Once StaffPad recognizes it, it behaves just like any hairpin created with the Symbols palette.