Need to get your house cleaned, and want to use an online service to schedule that cleaning? It seems like there's no shortage of startups looking to help Seattle residents do that. EXEC, a Y Combinator startup out of Silicon Valley, said today that it has launched into the market, to help residents find and book a cleaning service here. Sound familiar? The launch of EXEC into the market comes only a few weeks after another, Silicon Valley startup, Pathjoy, launched its own, online-house-cleaning marketplace service here, as well. Exec is headed by Justin Kan, best known for life casting himself through Justin.TV.