For all Android users not using Google Play:
Version 3.1 of Keypad-Mapper 3, the most efficient app for mapping addresses and house numbers, is now available in the F-Droid app store …
https://f-droid.org/repository/browse/?fdfilter=keypad&fdid=de.enaikoon.android.keypadmapper3
…and in the Amazon app store:
http://www.amazon.de/ENAiKOON-GmbH-Keypad-Mapper-3-OpenStreetMap/dp/B00C4UP86K/ref=sr_1_1?s=mobile-apps&ie=UTF8&qid=1385041553&sr=1-1&keywords=keypad-mapper
Have fun with mapping house numbers and addresses!