I was having a play at the weekend and discovered that Quickoffice HD on the iPad (and presumably Quickoffice Pro on the iPhone) actually makes a pretty useful Google Drive client.
You can view/edit docs, view photos etc. You can even upload docs - not much else, but then it was never designed for anything else.
I was actually pretty impressed with just how much I could do with it. Moving/deleting files works a treat, too.
If you've already got Quick Office, and were looking for a Google Drive client, you've already got one!
I'm guessing this is at least partly why Google acquired them.