The first applications supporting Apple’s new iAd mobile advertising platform have appeared on the App Store. Avantar, developer of mobile search applications such as OneTap Movies, Showtimes, Munch and Yellow Pages, has updated several of its applications integrating the new mobile advertising platform. Apple’s iAd does not go live until July 1st, and at this time these apps appear to be showing either a test ad or an empty banner. The…