With app stores providing the basic backend delivery system for games and apps, the race is now on to create decent cross-platform discovery channels.

So, alongside brute force deals such as Facebook and Twitter, or social gaming networks - OpenFeint, Scoreloop etc - we're seeing a new generation of targeted social and recommendation engines such as TeePee and mobile9.

The Malaysian-based multi-platform mobile aggregator already claims over 30 million users, of which around 6 million have registered with it, and has hosted 9 billion downloads since it was launched in 2003.

Phone a friend

As well as pushing apps, it also handles wallpapers, videos, screensavers, ringtones and themes, and in terms of platforms, it cover everything from Android, iOS, Java, Palm and Flash to Symbian and Windows Mobile.

Now, it's building a social layer on top of its infrastructure via the mobile9.com site. This enables you to see a real-time stream of what apps and content your friends are using.

"Our users are actively downloading mobile content, and that's exactly the right audience for developers," said Patrick Ooi, mobile9's founder.

"Developers can push apps and marketing messages straight to our users. The latter can then recommend to their own friends and so on. Good apps will explode virally."

You can see how it works in the following video.