The free app per day app, AppGratis, was pulled from the App Store yesterday. Many assumed that AppGratis was pulled from the App Store because of Apple's new 2.25 clause regarding apps that promote other apps in a similar manner to Apple's own store.
2.25 Apps that display Apps other than your own for purchase or promotion in a manner similar to or confusing with the App Store will be rejected.
Apple has confirmed that AppGratis was pushed out of the App Store because it violates clause 2.25. Apple added that it also violates clause 5.6 that prevents using Push Notifications for advertising and promotions:
5.6 Apps cannot use Push Notifications to send advertising, promotions, or direct marketing of any kind.