Want to be able to sign documents on the go? You can download the Android DocuSign app and prepare documents for signatures from inside the Google Docs interface. Need to add complex annotations to a document while riding the train? Use EasyBib to streamline the process. Users can add ProsperWorks to import CRM data, AppSheet to generate mobile apps from data sheets, Scanbot to capture physical documents with your smartphone camera and more.

While these add-ons seem like a great way to be more productive on your phone, there's not very many of them. Google's Docs and Sheets add-on page on Google Play lists just nine compatible apps -- a far cry from the massive library available to desktop users -- but it's a start. Check out Google's announcement post for more details.