Google Drive is Google's file sync app that lets you store all of your files online alongside your Google Docs documents, and keep them synced with all of your devices.
Record signature request links on the right client cases.
Your signers get the agreement to sign, and you can see the request link and sent status on the case.
Send the approved agreement and record which version went to signers.
Your agreement goes to the right signers in the order you choose, and the case gives its owner a link to the request.