http://sn.1w6.org/file/mk-20140606T181039-rm962cq.html
@mk the #OSM app didn't work out so well for me in Vienna, but proved extremely useful in Istanbul. Its biggest point over #Google maps is that you can pre-download maps (when you have a free Wifi connection, for instance) and thus don't have to pay for data when using it. It can use GPS (which eats battery), but phone radio towers usually give accurate-enough location (if you need 'present location' at all!)