Irvine-based Foundation 9 Entertainment, the videogame developer headed by James North-Hearn, said Thursday that it is now the leading developer of games for Xbox Live Arcade. Foundation 9 bragged that it has nearly 15% of the more than 300 games available through XBLA. The firm saidd that its top five XBLA titles have generated more than $22M dollars in revenue for the firm. Foundation 9 is backed by private equity firm Francisco Partners.