Sketch Measure - Spec tool for developers and teammates
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
Brandy - Keep brand assets in sync with your team and right at your fingertips for quick use.
Marketch - Marketch is a Sketch 3 plug-in for automatically generating html page that can measure and get CSS...
Brandfolder - One link to all your marketing assets. Brandfolder is your convenient source to visually organize, quickly find and easily share all your final brand assets.