Heurio is a web application and browser extension that allows teams to collaboratively review and provide feedback on websites. Some key points:

– Users can turn on the Heurio extension to add comments, feedback, and annotations directly onto any web page. These “heurios” can be color-coded by severity. 

– Projects and team members can be managed in the Heurio web app. Users can invite others, share links, or export feedback to PDF.

– It supports common usability evaluation methods like heuristic evaluation and provides guidelines. Teams can also create their own principles. 

– Feedback indicates it saves time versus other tools and allows remote collaboration. Pricing tiers are available for individual and team plans.

– The company aims to make the design, development and marketing process more efficient through collaborative real-time feedback on websites.