"QuickDic" offline Dictionary App for Android. Provided downloadable dictionaries are based on Wiktionaries but can also be created from other sources (see DictionaryPC). Remember to use --recursive when cloning! Fork of project that used to be hosted at code.google.com/p/quickdic-dictionary.
rdoeffinger/Dictionary has 398 GitHub stars.
It currently ranks #11633 daily, #12692 weekly, #16189 monthly by momentum on Trending Repos; its best-ever rank is #5279.