One of the hallmarks of Google Docs (and now Google Drive) is that you can use it anywhere. Within reason, any device with a modern web browser can deliver some level of viewing, editing, and collaboration. On iOS devices, however, native Office-style apps like Quickoffice tend to deliver a somewhat better user experience and are capable of opening, editing, and syncing documents with your Google.
There’s a clear value for such capability on an iOS device in that most apps deliver a better experience than Google Docs running in mobile Safari. Is there a similar need on the desktop? Would a native app a better solution than using Chrome or Safari on your Mac? According to Mac/iOS developer Tricky Duck, the answer is yes.