• by Wayne Friedman , April 2, 2009

TV shows are expanding their digital tools for promotion -- and one growing area is the iPhone.

Recently, Taxi New York created an application for the iPhone and the iPod Touch for the new limited CBS drama series "Harper's Island," a 13-week murder mystery surrounding a weekend wedding on an island near Seattle.

The show premieres -- along with the iPhone app -- on April 9.

The difference with this effort, says Rich Muhlstock -- general manager of content at Taxi NewYork, where some early mobile efforts for TV shows focus on games -- is that it delivers specific video and other content.

"This is not a game; [this is] more entertainment," says Muhlstock. "I would think it would help drive greater engagement, tapping into a new audience."

For example, he says users can explore locations where mobile users can "pick up conversations" from other wedding party guests. Users can go to locations to see where people have died -- and guess where the next murder will occur.

Taxi New York did not have a previous relationship with CBS. It just pitched the idea outright. The company may be working with the network on future shows.

CBS has other digital efforts working for the show, including a fictional social site/newspaper Harper's Globe, produced by EQAL, the design firm behind lonelygirl15.