When I followed the app's unique iTunes URL Tuesday, iTunes returned a message saying it is "not currently available in the U.S. store." When I tried searching for the app, no listing was displayed in the results. Last week, a search for "DS Double" returned the app's listing in those same results.
It shouldn't come as a surprise that the DS DoubleSys app was removed from the App Store. It seemed to me that it was just a little too similar to the Nintendo DS. And since it mimics the Nintendo DS' operation, its menu, and even some of its sounds, I can only bet that Nintendo wasn't happy with it.
At this point, there's no word if ZM2 Dev, the app's developer, is even aware that the app has been removed from the App Store. The company's Web site still lists it as available in Apple's marketplace. In fact, it's bragging about its sales. ZM2 Dev said its app was the eighth most popular paid music game in the U.S. App Store. It was the 72nd most popular app in the store's Arcade listing.
DS DoubleSys is no longer on either of those lists.
The disappearance of the app follows a long line of apps that have been rejected or booted from Apple's App Store. Apple initially allowed DS DoubleSys into its App Store. Although it's possible that Apple thought better of it and decided on its own to remove the app, it's more likely that Nintendo played a part.
At this point, it's still a mystery: neither ZM2 Dev nor Nintendo immediately responded to requests for comment.
Update at 1:53 p.m. PDT: The YouTube video ZM2 Dev used to promote the DS DoubleSys app has been removed from the video site. When users try to play the video, it displays a message that provides more evidence that Nintendo might have been behind the applications removal from the App Store: "This video is no longer available due to a copyright claim by Nintendo of America." (Thanks, mista77.)