If you have used an iPhone, one of the minor annoyances is that all of the numbers and punctuation are not shown when typing; you have to hit the .?123 key to display those keys. To type a key on this part of the keyboard it takes 3 clicks: one to get the .?123 keyboard, one to select your key, and one to press the abc keyboard to get back to the letters. Turns out this can be turned into a single click with a swipe.

If you want a period or comma on your iPhone, touch but do not release the .?123 key to get the alternative keyboard then slide your finger to the key you want and release it. This will give you the key you were on when you removed your finger, and more importantly, it'll take you back to the regular letters on the keyboard.