I post these as an Android user, but they should work in iOS too.
  1. Google Translate
    Hit the camera button, point it at some text, and boom! Instant translation.
  2. Google Inbox
    Save links for reading later. Just open the app with a URL on the clipboard and tap the blue link button.
  3. Search
    Search for "my bills" and see all your recent bills from your Gmail account.
  4. Google Maps
    Start navigating to a business, and the app will warn you if the business will be closed by the time you arrive.
  5. Google Calendar
    Include an address in an appointment, and a map of the location will be used as the background for the entry in the schedule view.