BASIC USAGE
Swipe left or right to change the view.
From left to right you move from Month to Week to Day.
You'll always go to the Week or Day on which you start the swipe.
Swipe up or down to change to the previous or next Day/Week/Month.
ADVANCED USAGE
Fast scrolling: swipe up or down with 2 fingers to move 7 Days/4 Weeks/12 Months at a time.
Volume key navigation: use the volume keys to navigate up or down, in normal or fast mode (configurable in Settings - Gestures & Buttons).
Agenda shortcut: In Day view, tap on the date, to go to Agenda View (and vice versa).