Content Snare popularized checklist-based document requests for client-facing teams. ClientBrief takes the same core idea — send a checklist, get uploads, skip the email chaos — and keeps it simple.
Content Snare is a capable tool, but its plans are priced per active request and per user (roughly $29-35/month and up for 2 users and 20 active requests, scaling higher from there). If you just need a fast, no-login way to collect documents from an unlimited number of clients, that's overhead you don't need.