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.
List exact copies across record folders with links to originals.
Get a linked review list of exact copies across your shared folders, with extra files marked where they sit so you can decide what to keep.
Mark exact copies in incoming records before review.
Spot repeated files before you review a team's batch. Your folder shows flagged copies, and a results file shows where their matches live.