Hikes on the web
Lower Austria (Niederösterreich)
Lots of hikes in Lower Austria, with descriptions from the newspaper "DerStandard".
An app with lots of hikes and good maps
Online map for all of Austria - unfortunately not very user friendly but the maps are good
Great maps for hiking, for all of Europe
A very good shop for buying maps for Austria, Europe and around the world. Also lots of travel guides, and outdoor sports guides, including a lot in English. Online or at their shop, Wallnerstraße 3 in Wien 1.
The best App I know for mapping. The last version is only available on this website, not on Google Play.
http://www.bergsteigen.com/A comprehensive guide to just about all climbing routes, via ferratas, skitours and much much more in Austria. The site is in German, but with help from google translate and the topos and photos, you can get some good ideas for your next trip