Good maps as good graphics are worth a thousand words and should be shared. Here I collect some links to maps and corresponding apps with the focus on community projects. Amazing Maps frequently tweets interesting and curious maps. 

Maps

• https://www.openstreetmap.org - many others projects are based on this open map. Participate!
• http://www.openweathermap.com - uses Open Street Map and weather sensors for weather forecasts
• http://www.opencyclemap.org - Open Street Map with bikeways
• http://mundraub.org - Open Street Map mit Fundstellen von Obst- und Fruchtgewächsen
• http://www.basemap.at - die Verwaltungsgrundkarte von Österreich
• http://www.anachb.at - Austrian route planner even for bikes and public transport. An Android app exists as well.
• Infrastruktur-Karte der Österreichischen Bundesbahnen
• Netzpläne für Wien: Netzplan Wien, Nightlines, Flughafenverbindungen, Linienverläufe der einzelnen Linien von S-Bahn, U-Bahn und Straßenbahn

Apps of Android

• OsmAnd  - open-source, map, and navigation app for Android. It uses Open Street Map among others and supports download for offline use.
• AnachB|VOR - anachb.at for mobile phones