Another day, another lawsuit. Walker Digital, founder of travel site Priceline.com, has filed its second patent infringement suit against Apple, “taking aim at the iPad and a digital media application available for download on its App Store,” reports “AppleInsider.”

The complaint from Walker Digital accuses Apple of patent infringement alongside the Walt Disney Company, The Weather Channel, The Nielsen Company, Digimarc Corporation, and TV Aura Mobile. Walker Digital claims the companies violate its patent (number 623505) involving a system that synchronizes additional media, such as separate audio or video, with a program that is being played either live or a recording that is being replayed.

Apple is named in the lawsuit not because of any applications it has made. Rather, the lawsuit names software that is available on Apple’s App Store, including “From the Edge” and “ABC’s Grey’s Anatomy Sync,” which can be run on the iPad, notes “AppleInsider.” Earlier this month Walker Digital filed suit in Delaware to stop the unauthorized use of its intellectual property rights and to recover its substantial investment in innovation. In total, 15 suits were filed against more than 100 defendants, including Apple, Microsoft, eBay, Amazon, Facebook, WalMart, Groupon, Sony and Google.

Walker Digital Chairman Jay S. Walker is the founder of Priceline.com, Synapse and other companies. He’s also the lead inventor on a majority of the company’s patents and applications.

— Dennis Sellers