Facebook prepares Android 'takeover' - Telegraph Android is developed by Google, Facebook's main rival for digital advertising revenue. Mr Zuckerberg has however praised the operating system as a "very dynamic and open platform" and called on Google to "keep it that way." In recent months he has encouraged staff to use Android as well as iOS, Apple's mobile operating system, which accounts for most of the rest of the global market. By mounting an effective takeover of Android, Mr Zuckerberg aims to increase the amount of time mobile internet users spend on Facebook, without the risk and expense of developing his own hardware, or software from scratch. Mobile advertising accounted for almost a quarter of revenues last quarter and Mr Zuckerberg has insisted that "there's no argument, Facebook is a mobile company." Facebook members are rapidly migrating from the full website to smartphone and tablet versions and mobile users now outnumber desktop users on a daily basis. The trend alarmed investors when the firm floated on Wall Street last May. Two quarters of rapid growth soothed nerves, but a major internal reorganisation to focus on the mobile internet is ongoing. Apple maintains much more strict control over iOS than Google does over Android, making a similar Facebook takeover unlikely. After settling a long-running fued, Apple has integrated some of the social network's services into the iPhone, however. It was reported on Wednesday that Apple will begin producing the next iPhone, likely called the iPhone 5S, this quarter, in time for a summer release.