gvSIG Mini is a free viewer of free access maps based on tiles (OpenStreetMap, YahooMaps, Microsoft Bing, ...), with a WMS, WMS-C client, address and POI search, routes, hybrid location and many more things. It runs with both on/off-line modes.
1) Full list of Features available here.
2) Multiple Map Layers (satellite images and standard maps).
3) Low bandwidth usage and offline usage
4) Maps downloader from the phone.
5) Support for WMS and WMS-C layers
6) Layer configuration downloader
7) Address and Points Of Interest search
8) Route finder
9) Compass support and Navigation Mode
10) GPS, Cell and Network GeoLocation positioning
11) Share your location: Twitter, SMS, Email, Facebook...
12) Street View integration
13) QuickZoom: SlideBar or DoubleTap
14) Compatible with Low and High Screen Resolutions. Portrait and Lansdcape orientation.
15) Free to use (GNU/GPL)