Achievements 4 Halo 4 has been removed from the Google Play Market due to a takedown notice. This has affected 9 other apps in the Google Play Market.
REASON FOR REMOVAL: Alleged copyright infringement (according to the terms of the Digital Millenium Copyright Act). Not quite sure how it is causing offence to Microsoft but there you go...it won't be going back up.
#Update Now I know why...Microsoft updated their 'Game Content Usage Rules' towards the end of last year. http://www.xbox.com/en-US/community/developer/rules I will no longer be releasing any 'Achievement 4' apps for any Microsoft Published games. The following have been removed from Google Play Achievements 4 Forza 4