San Francisco-based Zynga, which develops social games, claimed today that it is now seeing more than 10 million daily active users across its games. The firm is venture backed by Kleiner Perkins Caufield & Byers, IVP, Union Square Ventures, Foundry Group, Avalon Ventures, Pilot Group, Reid Hoffman and Peter Thiel. Zynga distributes its games through social networking sites like Facebook. Its titles include Texas Hold'Em Poker, Mafia Wars, YoVille, and Scramble. According to Zynga, it is now the number one Facebook app developer.