Ranked in these QuestionsQuestion Ranking
Pro Complete offline wikipedia database
Not only can some pages can be downloaded for offline view, the whole of wikipedia can be stored on sdcard for offline access to all articles.
Pro Can open ZIM-database files
Uses a database called ZIM with an open architecture.
Pro Open source under GPL
Con No online viewing of wikipedia articles
A database with wikipedia articles must be downloaded before, otherwise you will not see any wikipedia article.