Goto Settings and select Accounts and Sync then select Add Account under manage accounts (may vary from phone to phone)
android
Google Inc. Introduced Android OS
Android OS for mobile.
Google currently owns and develops Android OS.
Yes. and Yes ...
Google Play is the application store for any Android OS software, as well as a store for videos, music, and books.
No. Android OS is not developed from "Microsoft". It is made by "Google". Check out this site. It will tell you all about Android OS. https://en.wikipedia.org/wiki/Android_(operating_system)
works on all android os v 2.2 and higher.
I think you mean Android :) Android is google's platform/OS for mobile devices.
Though Google Play (previously called Android Market) is generally available for Android OS 2.2 and above, it may be limited for use on devices with Android 2.1, and/or the device itself might not be compatible to use it.
Sundar Pichai oversees Android (and Chrome OS). Andy Rubin was the previous head of Android.