Ziflow - Online Proofing software from Ziflow keeps teams connected and collaborating by providing a single source of truth for creative review and approval.

Elyse - The free version allows up to 30 tags.

GoVisually - GoVisually empowers creative teams to deliver better designs, by providing a simple way to review and approve designs quickly and easily

DEVONthink - DEVONtechnologies develops DEVONthink, DEVONagent, and other Mac and iOS apps for document and information management and web research.

PageProof - Online proofing of anything and everything, made simple. Streamline feedback for easy collaboration, secure workflows, and faster approvals. PageProof. The smarter way to review.

Leap - With Leap you find things based on your natural memory of that file.