Android Apps
This app shows public book cases on a map screen, so you can easily locate them. All information in regards to the public book cases is originating from openbookcase.org.
With the POI Assistant app you can use POI files in OV2 (TomTom) format on your Android smartphone in order to find different kinds of POIs in the sourrounding area (i.e. cash machines, gas stations, fast food restaurants, ...).
The Sea Maps app allows you to view the OpenSeaMap nautical information layer on top of Google Maps. You can optionally toggle an option to follow your position or center on your current location.