可以隨時隨地將smart phone/tablet/PC 變成off-line GPS..

by
- downloading "NavigatorFree" or similar Apps using wifi, which allows for the installation of
- "OpenStreetMap" of any part of the world, again thru wifi.
Your smart phone then becomes a fully functional GPS, with no need of data connection.
The same can be done to a tablet or laptop (with the addition of a USB GPS module).