Proof HQ - ProofHQ provides a medium for co-workers to annotate and collaborate before producing a clean, finished output.
ReviewStudio - ReviewStudio is an online proofing software built for easy collaboration on review and approval workflows, for all your image, video, web pages and PDF based projects.
ProofHub - Project management and team collaboration software
Filestage - Filestage is a review and approval platform that helps you share, discuss, and approve all your files, all in one place.
Dizply - Dizply simplifies the process of managing and production of ad formats for ad agencies, media houses, and freelancers.
Ziflow - Online Proofing software from Ziflow keeps teams connected and collaborating by providing a single source of truth for creative review and approval.