When you are outside your own country, you probably want to use an Android navigation app without having an internet connection, as prepaid SIM cards are not available everywhere, and the roaming costs are high. In the following, I list some navigator apps that may help you.
|App||Description||Vector maps||Image cache||Navi function||Cost|
|OsmAnd||OpenStreetMap navigator and map viewer. It works both with image tiles and with vectors maps, and can cache vector maps in advance.||x||x||-||free|
|Maps (-)||Tile-based map viewer and uses OpenStreetMap or Google maps data. It can cache regions on different levels, although this takes a lot of space. It has no navigation functionality.||-||x||-||free|
|Maverick||A GPS track app with added maps. It cannot cache (can it?)||-||-||-||free|
|Skobbler||Two apps: ForeverMap lite, a viewer, and skobbler, a navigator. German only. Requests strange permissions.||-||x||x||free|
|Navigon Copilot||On the commercial side, Navigon and Copilot still rule the pack, with NDrive somewhat behind. iGO does not support Android anymore.||x||x||x||money|
|My Tracks, Navigation and Maps have limited caching (up to 6 regions) abilities, but mostly rely on internet connection.||-||x||-||free|
My current choice is OsmAnd. In Settings->Map Appearance->Map tile source, choose "Vector OSM maps", then in Settings->Data for offline usage->Download offline data, download the vector maps of your liking. Then off you go.
Update 2012-01: Moderately happy with OsmAnd for 6 months. Sometimes displays land as water and vice versa, if you are near a coast. On slow phones (such as my travel LG P350 Optimus) slow map update. Still, it is the only free vector-based navigator I could find. OsmAnd data often has no house numbers.EOF (Jan:2012)