UseResponse - Open-source, self-hosted customer feedback software, live chat and helpdesk system that you can install on your server. Organize documentation using knowledge base and get feedback from social networks with centralized system
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
UserVoice - UserVoice integrates easy-to-use feedback, helpdesk, and knowledge base management tools in one platform that empowers users to speak and companies to understand.
Invision - Prototyping and collaboration for design teams
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
Sketch - Professional digital design for Mac.