If you’re still hanging on to a phone running Android 4.0 Ice Cream Sandwich, you might want to budget for an upgrade. Google has warned developers that it’s deprecating support for Ice Cream Sandwich in upcoming versions of Play Services, the framework that gives Android apps and devices access to key features without requiring full-fledged operating system updates. Existing developer kit elements will continue to work, and individual components may continue to support the OS going forward, but “many” newer toolkit iterations will require at least Android 4.1 Jelly Bean.

Source: Android Developers Blog