What is the codename of Android 4.0?

The codename of Android 4.0 is Ice Cream Sandwich.

Released in 2011, Android 4.0 was the fourth major version of Google’s mobile operating system. It followed Android 2.3 Gingerbread for phones and Android 3.0 Honeycomb for tablets, combining the two branches into one version for smartphones and tablets. The first phone to ship with it was the Samsung Galaxy Nexus.

Ice Cream Sandwich introduced Google’s Holo visual style, the Roboto typeface, on-screen navigation buttons, improved widgets, Face Unlock, NFC support, and tools for monitoring mobile-data use. It was intended to make Android’s interface cleaner and more consistent across different screen sizes.

A common mix-up is confusing Ice Cream Sandwich with Jelly Bean or KitKat. Jelly Bean followed it as Android 4.1, while KitKat was Android 4.4. Android 4.0.3 arrived later with bug fixes and additional APIs, and Android 4.0.4 added further performance improvements.