Loop is a Mac app for the files you already make elsewhere: a PDF, Keynote slides or a Pages document. Drop one on Loop and it becomes your own branded link that readers mark up and sign in order, with the time spent on every page shown back to you. Nothing is rebuilt in an editor, and your files stay in your own Cloudflare account. It costs $49 once, where PandaDoc's Business plan, the first with your branding, is $588 a year.
Loop has no proposal editor, quotes or CRM, so you write the document elsewhere. Loop vs PandaDoc goes through every difference.