Facebook launches App Center amid worries over mobile revenue Facebook has launched an online store to allow consumers to find apps and games on the social network. The new function includes the Facebook's first storefront for selling paid for apps. The App Center comes as Facebook prepares an initial public offering (IPO) at between $28 and $35 per share, valuing the company at between $85bn-$95bn (£52bn-£59bn). The IPO is set to be the biggest ever for an internet firm. The decision to launch the new app store also comes as concern grows over Facebook's slowing revenue growth - which thought to be in part due to the growing trend of users accessing its service on smartphones - where the social networking site provides only limited ads. Developers will be able to sell apps in the new store, and charge a fee in the near future. Today's announcement came as Facebook admitted concern over the growth in mobile technology and users accessing the social networking site via their phones. Facebook said in a statement ahead of the IPO, "If users increasingly access Facebook mobile products as a substitute for access through personal computers, and if we are unable to successfully implement monetisation strategies for our mobile users, or if we incur excessive expenses in this effort, our financial performance and ability to grow revenue would be negatively affected." Facebook said today that the App Center would be released globally in the coming weeks. The company currently makes the majority of its revenue from online advertisements, but it also collects a fee when consumers purchase items from within social apps, like Zynga's Farmville. The App Center will, for the first time, allow developers to sell apps to consumers directly on Facebook. Apps are extremely popular activities with Facebook's 900 million users. According to the company, 200 of the apps that are available on Facebook currently have more than 1 million users.