PDF, JPG and PNG. Screenshots are fine. Order them the way the reader should see them.
What it does. Takes the pile of PDFs, scans and screenshots you already have and turns them into a single packet: a cover page, an index whose page numbers actually match, a tab sheet before each exhibit, and a stamp on every page — A-1 style for courts that letter their exhibits, or continuous Bates numbering if you need that instead.
What it costs. Nothing. There is no account, no sign-up, no email, no trial.
Where your files go. Nowhere. The page carries a connect-src 'none' content-security policy, so it cannot open a network connection at all — not to me, not to anyone. Press F12, open the Network tab and build a whole packet; it stays empty. The Prove it button above demonstrates the same thing.
What you need. A desktop or laptop browser. Password-protected PDFs from banks usually open without asking; if one needs the password you type to open it, the tool will ask you for it.