Only on 4.0: it represents less than 1.5% of all Androids now. iOS had Websockets since 4.1, for over 1.5 years. Unless Chrome gets back-ported to Android 2.2 and 2.3 it will take a very long time.
https://github.com/LearnBoost/socket.io/issues/193
Pretty annoying.
http://developer.sonymobile.com/wp/2011/12/07/ice-cream-sand...