Google Drive for iPhone and iPad has been updated with improved collaboration and on-device sharing. Users can now create, edit, and collaborate on spreadsheets and upload to Drive with other apps using "Open in..." There is also a new Uploads section that allows you to manage upload progress and see recent uploads.
The ability to edit spreadsheets has been one of the biggest user requests, so it's great to see Google respond by including that ability. It still isn't possible to update presentation, but hopefully that will be coming in the future as well.
Google Drive is a Dropbox-like service that lets you store documents pictures, and other files and share them with whoever you want. A free account includes 5GB of storage space with options to upgrade to 25 GB and 100 GB for $2.49/mo and $4.99/mo, respectively.