A variety of mobile apps provide access to Wikipedia on hand-held devices from Apple. These apps are accessed via Apple's App Store, a digital application distribution platform for iOS. This represents an important new way that the public is accessing Wikipedia. Some apps load content from the Wikipedia site and process it; other apps use the MediaWiki API.
For each listing, to give a flavor of the app, 1-2 sentences from the app developer's promotional blurbs are listed for each. To limit this list to only notable apps, only currently available apps listed in major app blogs like "148 Apps" or traditional news/media are included, with closely similar apps condensed to one. Also, only English-language apps are listed.
- All Of Wikipedia - Offline -- by Brilliant(ish) Software -- Offline is the fastest, most frequently updated, and fully featured completely offline Wikipedia application available for iPad and iPhone/iPod. Sync once and you'll never need a connection again to have every single article on Wikipedia. 
- Discover — Wikipedia in a Magazine -- by Cooliris, Inc -- Discover is a completely new way to explore Wikipedia, inviting you to sit back, relax, and expand your knowledge through a delightful experience that doesn't feel like you're reading an encyclopedia.
- Simplepedia for iPad — Simple Wikipedia Reader -- by realazy -- No eye candy, focus on READING. Simplepedia.app is a simple Wikipedia reader which can automatically save articles for offline reading, support 70 languages. - Fast search, fast languages switch - Comfortable reading experiences, hyphenation enabled - Quick font sizes adjustment - Table of Contents (chapter selector)for easy navigation - Find in page - Auto saving articles for offline reading, images ... (This is a suite of apps with different price points. )
- Wiki² - Wikipedia Reader for iPad -- by BananaGlue GmbH -- Experience Wikipedia in a new, easy and beautiful way. Every article you look up is stored on your iPad for offline reading - no internet connection is needed. Wiki² was chosen as "New and noteworthy" in April 2010. • Search and find very quickly what you want to know • See preview images in most search results for easier and ...
- Wikibot -- A Wikipedia Articles Reader -- by Avocado Hills -- Wikibot makes reading Wikipedia articles a joy on your iPhone, iPad, and iPod Touch. Between the beautifully crafted interface, customizable display options, and killer features like tabbed browsing, language switching, a read-later queue and offline caching, there is a lot to love about Wikibot! ...
- WikiNodes -- by IDEA.org -- WikiNodes puts the knowledge of Wikipedia at your fingertips. Articles are displayed as nodes that you can touch, drag, and spin around. Tap any node, and it expands to give you more information. Or, switch to a full-page view to display articles as pages, then scroll up and down. Nodes link together sections of Wikipedia articles and related topics, making ...
- Wiki Offline -- A Wikipedia Experience -- by Avocado Hills -- Wiki Offline delivers flexibility and joy for the Wikipedia experience. The full text of all Wikipedia articles are stored to your iPhone/iPad/iPod. You will literally hold the world's knowledge in the palm of your hands. No more worrying about slow internet connections, overage bandwidth charges, or traveling to areas without internet, because with Wiki Offline, Wikipedia will be there for ...
- Wikipedia Mobile -- by Wikimedia Foundation -- Official application. Focused on being very simple and very fast. Over time, they will add features based on requests. The code is 100% open source and community built. 
- Articles -- by Sophiestication Software -- Articles features a one-of-a-kind presentation of Wikipedia articles, perfectly optimized for iPhone and iPod touch. It is a beautifully designed example of an app that does one thing really well, and shows off the value of a quiet browsing experience. 
These apps primary objective is to play games, such finding a path from one article to another by following links, in a manner similar to Word ladders.
- 3 Degrees of Wikipedia -- by Ivan Zhao -- What happened to the hundreds of Wikipedia articles you have read? "I forgot about them", you answered. Here is a game to help you remember those forgotten articles, and it will stimulate your brain like nothing else. The idea is very simple: in each puzzle, you will be given two Wikipedia pages, and your goal is to navigate from one ... 
- Wiki Golf -- by Jesse Daugherty -- Ever wondered how to get from the Sun to London? How about from Uranium to Water? Wiki Golf is a game that lets you test 6 degrees of separation… and puts your skills to the test with Global Leaderboards!
- Wiki Hunt - The Wikipedia Game -- by Dan Hassin -- Wiki Hunt is a new and intriguing game of linking two unrelated Wikipedia articles in the least amount of clicks possible. Navigate your way from one article to another via the links in the connecting articles. Challenge friends to see if they can link them in fewer clicks or if they can discover your path at all! ... 
Topic-focused viewers & geolocation
These apps tend to be focused on a specific topic, or type of information. They are not intended to browser all of WikiPedia.
- Wikipedia on Map -- by Maksym Tsanko -- Get the value of places you never knew before! Explore the World! Read Wikipedia pages related to selected place on the map on any Language. Send interesting pages by E-mail to your friends or yourself. You can chose place by searching address, dropping pin on the map or get your current ...
These apps are designed to be visually intriguing, not specifically to be highly usable.
- POLY Wikipedia -- by CedeSoft -- Turn your iPad into a true Futuristic Access terminal with POLY Wikipedia for iPad using a unique Polygon based interface. POLY Wikipedia has been created from the ground up to present Wikipedia articles in a genuine futuristic Interface using animated text display and futuristic sounds. Article Summary Mode Tap the Article Summary button to put POLY ...