Balsamiq - Balsamiq. Rapid, effective and fun wireframing software.
Identihub - Self-hosted Open Source brand & assets management software
Invision - Prototyping and collaboration for design teams
OpenBrand - OpenBrand helps designers, agencies, and brands work together. It is a smart home for all your logos, designs, and other creative stuff.
Zeplin - Collaboration app for UI designers & frontend developers
Branding Guide - Streamline brand management with online brand guides.