1、GPS Data Tracker is an android app that displays the current GPS position fix as well as GPS constellation information (satellite visibility, signal strength, etc). The user can record a track where both the position fix and the constellation status are saved during a test.
http://code.google.com/p/gps-data-tracker/
2、Geopaparazzi is a tool developed to do very fast qualitative engineering/geologic surveys. Even if the main aim is in the field of surveying, it contains tools that can be of great use also to OpenStreetMappers as well as tourists that want to keep a geo-diary.
http://code.google.com/p/geopaparazzi/
3、Custom Maps makes it easy to create GPS maps from map images, and those maps can be used anywhere without data signal for your Android device.
http://code.google.com/p/custom-maps/
4、yozi Outdoor navigation software for Android platform
yozi is a navigation software for Android platform. It uses digital topographic maps in well-known Ozi Explorer formats for navigation and doesn't require network access like built-in Maps application on Android.
http://code.google.com/p/yozi/
