Greystripe, a SF start-up developing free, ad-supported games for mobile phones, joins a large crowd of competitors, raising $1.2 million in a first round of funding, according to VentureWire today (sub required).

The money comes from Incubic Venture Fund, Monitor Ventures and WS Investment Company, the venture arm of law firm Wilson Sonsini Goodrich & Rosati P.C. The company is already thinking about raising another round, it said.