This app free on Google Play but it do requires Office 365 subscription to use.
In terms of functionality its very much similar to iOS one and it includes apps like Word, PowerPoint and Excel. You can save files on SkyDrive or SharePoint, you can edit files while you are offline and they will be sync when you go online. You can also view recently opened documents and you can also open and edit email attachments.
To use this app you need to have Android 4.0 Ice Cream Sandwich or higher.