ZANavi for Android - Free opensource offline navigation

ZANavi for Android, the completely free and offline Navigation for Android
ZANavi for Android is an open source (GPL) car navigation system for offline Navigation

if you want better quality voice install:
https://play.google.com/store/apps/details?id=com.svox.classic
or
https://play.google.com/store/apps/details?id=com.ivona.tts

based on Navit
Features:
*) works on Ice Cream Sandwich (ICS) (Android 4)
*) support to show GPX files
*) Navigate to target from google maps
*) APP2SD
*) works offline (offline navigation)
*) world overview map
*) tunnels are visible on map
*) bridges visible on map
*) map turns with compass
*) map management (download/update/delete maps)
*) search offline OR online
*) spoken directions in many languages
*) uptodate OSM maps
*) follow mode OSD toggle button
*) oneway arrows [BETA]
*) select your language in the application
*) select search country
*) checksum downloaded mapfiles
*) announcer toggle
*) settings and menus translated
*) map preview on search results
*) aGPS
*) last destination list (bookmarks)
*) add waypoints
*) show waypoints on map
*) configure map data directory
*) full world map download (special donate version!)
*) configure cache size
*) configure font size
*) change search radius for streets in towns
*) free zoom level with pinch zoom
*) enter coordinates (lat,lon) manually
*) switch off mapdisplay (button on right top of screen)

Download link
ZANavi