Microsoft has been teasing it for quite some time, but they finally made it happen... Microsoft Office has come to Android officially. Intriguingly it is also FREE! Well... not really. You can download it for free, but you have to have an Office 365 subscription in order to use it.
There are two other things worth noting. One is you need Android 4.0 or higher to use it. The other is it doesn't work on tablets just yet. (This seems like a huge oversight doesn't it?)
Here's the Google Play Store link: https://play.google.com/store/apps/details?id=com.microsoft.office.officehub