From Steam Heavy Industries:
Encyclopedia provides a complete copy of the contents of Wikipedia on your iPhone or iPod Touch. No internet access is required to search and view articlesyou can browse everything without any internet or data connection.The app is the fastest and simplest way to browse Wikipedia. It works in a plane, on top of a mountain, in a tunnel, and when you're abroad. It's been featured in documentaries, and in publications like the New York Times and ZDNet.Encyclopedia also allows you to install multiple databases on your phone: you can pick from our supported Wikipedia, Wikitravel and Wiktionary databases. (The most popular one is, of course, the complete English Wikipedia.)When you first launch Encyclopedia, you will see a copy of France Wikitravel, and have the opportunity to download additional Wikipedia databases, such as English Wikipedia. (You need a wifi connection for these downloads.) The English Wikipedia will occupy about 2.6GB of space on your device. Regular updates to the Wikipedia databases are provided.For frequently asked questions, please head to http://steamheavyindustries.com/support.FEATURES No internet access required. Complete text of the English Wikipedia and/or the Wikipedias of your choosing*. Instantaneous search of article titles. Fully functional links between articles. Navigation trail, so that you can easily engage in the usual whimsical Wikipedia browsing. Bookmark support.REVIEWS "The only game in town" - ZDNet "One of the Seven Must-Have Offline Apps For Your iPhone/iPod Touch" - New York Times "It's the Hitchhiker's Guide to the Galaxy realised" - Desinformado "It was one of the reasons I bought an iPod touch" - Lennart N. "It's the best and most useful iPhone app I know" - Alexander C.AVAILABLE DATABASESWikipedia Encyclopedias: English Wikipedia Spanish Wikipedia German Wikipedia French Wikipedia Dutch Wikipedia Japanese Wikipedia Italian Wikipedia Irish Wikipedia Arabic Wikipedia Hungarian Wikipedia Indonesian Wikipedia Farsi Wikipedia Chinese Wikipedia Turkish Wikipedia Russian Wikipedia Finnish Wikipedia Vietnamese Wikipedia Hindi Wikipedia Greek Wikipedia Catalan Wikipedia Hebrew WikipediaWiktionary Dictionaries: Spanish Wiktionary German Wikitionary Italian Wikitionary and moreWikitravel Travel Guides: WikitravelSome parts of articles that aren't very useful on a mobile device (such as references) have been excluded, but all of the actual article text is preserved. In addition, only proper articles are downloadedimage descriptions, user profiles, etc., are not included.Please note that this application's developers are in no way affiliated with the Wikimedia Foundation. However, a portion of the revenues will be donated to the Wikimedia Foundation to support their work.
full iOS7 redesign and compatibility stability issues in 4.0 addressed now a universal app: iPad and iPhone/iPods supported even more languages added. in addition to English, a full 83 Wikipedia, Wikitravel, and Wiktionary database dumpsupdated in Summer 2013are available for free download with purchase of app.