It was a couple of months ago that BiteHunter.com beta-launched itself as an aggregator for dining deals. Easily described as a "Kayak for restaurants," BiteHunter is designed to help users locate dining deals, a problem which has been been addressed quite well for verticals such as travel, but quite poorly for dining, at least on an aggregated basis. Today BiteHunter is announcing a new iPhone app ( iTunes Link ) that expands its dining deal search across the US, from the initial markets of New York, San Francisco and Chicago.