Wikia is a free hosting service for wikis. In other words, it is a collaborative publishing platform that enables communities to discover, create and share content on any topic in any language. The spectrum of topics is very wide. Gamers can find information on different video games and gluten-free people can find recipes. Wikia has such a giant amount of information because all of the content is supplied by its user base (just like Wikipedia).
Android apps by wikia: https://play.google.com/store/apps/developer?id=Wikia,+Inc.&hl=en
iPhone Wikia gameguides: https://itunes.apple.com/us/app/wikia-game-guides/id422467074?mt=8