Android: LibreOffice is one of our favourite office alternatives, and it stands up well to the competition. If you need to read your documents when you're away from the computer, LibreOffice Viewer Beta can help.
The app supports reading a wide variety of file types including OpenOffice file types such as .odt, .odp and .ods, as well as Microsoft Office file types. So, no matter what document you have, you can read it here.
LibreOffice Viewer Beta [Google Play Store]