OpenDocument Reader is compatible with many other apps that allow you to download documents directly, including Gmail, Dropbox or Box.net. In addition, you can open any type of OpenOffice document: text files (ODT), spreadsheets (ODS) and even presentations (ODP).
Though OpenDocument Reader isn't directly affiliated with OpenOffice, this is a completely free, open-source app. So, it has some advertisements that allow its creators to make a little money off of it. Either way, these advertisements aren't at all intrusive.
OpenDocument Reader is an excellent tool for anyone who usually works with OpenOffice on his or her computer and needs to be able to view and edit documents directly from their his or her Android device.