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.
Keep document review handoffs supplied with current files.
Your internal reviewer sees current packet files alongside the form answers, while your team can resolve missing files before sign-off.
Return incomplete contract packets before legal review resumes.
Your requester sees exactly which contract files are missing, while the approval stays in correction for follow-up.