Apple is extremely protective of its trademarks, and has begun rejecting App Store submissions with "Pad" in the main title.
9to5 Mac notes that Jesse Waites, the developer behind ContactPad, has recently had an update for his app rejected because of its name (note that ContactPad is currently available; it's the update that was rejected). Apple has established a policy meant to eliminate confusion over which products were actually produced by Apple. Among the criteria is "...You may use Apple, iPad or any other word mark provided that...the Apple word mark is not part of the product name."
True, "Pad" isn't "iPad," but it's close enough in Apple's opinion.
This isn't the first time we've seen Apple request such a change. Website iLounge was previously named iPodLounge, and several years ago the makers of the iPed iPod stand were asked to reconsider their device's name (in no uncertain terms). More recently, the Little App Factory were told to change the name of iPodRip; a fix that Steve Jobs suggested was "Not that big of a deal."