CloudOn is likely the best way to use Microsoft Office on your smartphone or tablet. Sure, there are alternate solutions that allow you to create “true” Office documents with extensions that smell like the real thing, but there is no Office for iOS or Android.
CloudOn actually sets you up with a virtual Office shell, a windowed occurrence of Word, Excel or Powerpoint. It also acts as a cloud PDF or image viewer, allowing you to access documents saved on Box, Dropbox, Drive or SkyDrive.
Version 4.0 of the application introduces support for select Android smartphones (tablet support was added in the last version) such as Galaxy S III, Galaxy Note II and Galaxy Nexus. No Nexus 4 support at the moment, unfortunately. It also brings landscape typing support for all devices, including iPhone.
There are a number of other features in version 4.0, including a list of changes made to recent documents and some performance and bug fixes.