Quickly retrieve your last email draft!
Just put your finger on (and keep it on) the 'Compose' symbol (box with a pencil).
It will magically open the last email that you cancelled out of and chose to 'Save Draft' (if there is one!).
Very handy when you have more than one email account, and are not sure which account you used to draft the email.
Or when you just need to jump out of the email you are drafting to check another email, and quickly jump back into the draft.