Viewflux - Feedback, prototyping and collaboration for designers
Pastel - Sticky note-based feedback collection tool for live websites
Savahapp - The all-in-one design sharing, collaboration, workflow and app prototyping platform
MarkUp - Collect feedback on digital projects right in the browser.
Red Pen - Red Pen lets you upload your design, share a short URL, and get live, annotated feedback super-fast.
BugHerd - BugHerd: The Website Feedback Tool for Agencies