Google is often praised for its openness in cross-platform compatibility, most notably with iOS, Android's largest and most direct competitor. Unfortunately, this open-mindedness doesn't always benefit Google like in the case of Android's Google Play Games service. Given that iOS already has Game Center, the OS is not in need of another gaming service to clutter the default experience. As a result, Google has found very low usage of the service among iOS users. At the same time, it also found that Gifting, Requests, and Quests on the service were also quite low across both iOS and...
Source: http://www.gsmarena.com/google_play_games_services_no_longer_supported_on_ios_some_features_cut_from_android_-news-24378.php
