The recent update for Google Maps on iOS has brought along an easter egg first seen in Android. This easter egg allows you to save maps for offline use - a feature which anyone would find useful.
To save maps for offline use simply choose an area on a map, put 'Ok maps' into the search bar and hit search. The app will then start caching the area.
It works a treat and can be very handy for when your internet connection cuts out. It also saves on mobile data if you cache it over WiFi.