Mobile ad network Tapjoy launched its new personal app marketplace, a way of sifting through app clutter by offering individualized recommendations to users. The service uses factors including ratings, previous app usage, and which apps are being used by friends.

The app marketplace fits in with Tapjoy’s approach to deepening engagement, as shown in its Mobile Value Exchange, a system that enables users to select which from more than 100 advertising actions they’ll undertake in order to receive virtual currency or premium content. These actions are things like watching videos, subscribing to services, installing applications and purchasing discounted products.

Tapjoy has more than 35 million monthly active users, according to Mihir Shah, president and chief executive officer of Tapjoy. It supports iOS, Android Windows Phone 7 or HTML5-supported devices.

“Smartphone and tablet users are clearly eager for a better way to find new apps,” Shah said. “We’ve combined our personalized app recommendation engine and enormous app marketplace with social sharing and joint discovery features to create a unique and very personal app discovery experience.”

Tapjoy also offers its registered users social sharing, editorial reviews and recommendations, and a dashboard for managing installed apps and monitoring virtual currency balances.

Tapjoy investors include J.P.Morgan Asset Management, Rho Ventures, North Bridge Venture Partners, InterWest Partners and D.E. Shaw Ventures. Headquartered in San Francisco, the company also has offices in New York, Los Angeles, Chicago, London, and Tokyo.

Related links:

Tapjoy blog post –