Custom Maps is an essential app for Android phones for any serious off-trail hikers, sailors or anyone else who needs detailed off-line maps.

The app lets you quickly create a custom map for your Android phone from any map image or photo file. The image can be a photo or scan of a paper map. It could even just be the photo of a map posted at the beginning of a trailhead or at the entrance to an amusement park, which you can capture with your smartphone camera.

To create a custom map all you have to do is choose two (or more) points in your map image and plot them on a Google Map. That’s all it takes. Your finished map can then show your GPS location and will work even when a data signal is not available like in a state park or when abroad.

I have a boat that is moored on a river with lots of tributaries and creeks, some of which are navigable and some of which aren’t. When you start exploring these backwaters it is very easy to quickly lose a sense of where you are.

Using Custom Maps I made an off-line map for my phone in less than five minutes using a scan of a river chart. Now I should never get lost on my boat again.

The source code for Custom Maps is also available on Google Code. Several new features are also planned for the app including distance measurement, marking map locations with icons and making it possible to geolocate map images without Google Maps or a data connection.

Via: Open Source at Google