Flinto - The prototyping tool designers have been waiting for.
Whimsical Wireframes - Lightning fast wireframing with real-time collaboration.
Base UI Sketch Framework - Huge set of everything you need to design and prototype
Invision - Prototyping and collaboration for design teams
Glyphy - Copy & paste fancy fonts + cool symbols ☞✺✐™
Easometric Figma Plugin - With Easometric it's really easy to create isometric layers.