What are some alternatives?
When comparing Zeplin and Framer, you can also consider the following products
Invision - Prototyping and collaboration for design teams
Balsamiq - Balsamiq. Rapid, effective and fun wireframing software.
Proto.io - Create fully-interactive high-fidelity prototypes in minutes that look and work exactly like your app should. Sign up for a free 15-day trial and get started.
Webflow - Build dynamic, responsive websites in your browser. Launch with a click. Or export your squeaky-clean code to host wherever you'd like. Discover the professional website builder made for designers.
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
Flinto - The prototyping tool designers have been waiting for.