Android will remain the most-shipped smartphone operating system for the next five years according to the International Data Corporation, although Android’s market share will start to decline after 2012. Smartphone shipments are forecast to grow 38.8% year-on-year to 686 million units in 2012.

IDC’s Worldwide Quarterly Mobile Phone Tracker predicts a total of almost 1.8 billion mobile phones being shipped this year, a 4% increase from 2011’s total. This overall slow growth is mainly due to a decline in feature phone shipments. However, feature phones are still expected to comprise 61.6% of the total mobile phone market this year.

Google has acquired Quickoffice, which produces mobile office productivity applications for Android, Apple iOS and Symbian handsets.

Quickoffice enables users to access Microsoft Office documents and update them from a mobile device.

Enterprise IT business Citrix has agreed to acquire California-based Bytemobile, which it describes as a leading provider of data and video optimisation solutions for mobile network operators.

It notes that the acquisition expands its market reach by providing a foothold in the core infrastructure of more than 130 mobile operators in 60 countries. Both companies had formed a strategic partnership earlier this year.

Vodafone Group has taken a controlling stake in Invitation Digital Limited, the parent company of mobile coupon provider Vouchercloud. It now has a 57% stake in IDL, having originally taken a 21% stake in May last year.

The news came as Vouchercloud expanded beyond the UK into Ireland. Further country launches, along with details of Vouchercloud integration into Vodafone m-commerce activities, are expected in the future.

Facebook’s App Center, which the company describes as ‘a new place to find social apps’, has now launched on the Facebook web site and via its iOS and Android mobile apps. Announced last month, the App Center is currently only available to customers in the USA.

The App Center features existing Facebook-friendly mobile and web apps as well as new apps. Currently over 600 apps are available, with the service offering personalised recommendations.