Meet really fast tool for real-time collaboration called Figma. It’s like Sketch in the browser with possibility to handle dozens designers work on the same document at the same time.
As far as comparisons of Figma to Sketch is inevitable, we recommend you to read the full article and save your time: all the comparisons already made.
Every document and version in Figma exist on its server, making the task of iterating effortless and worry-free. You can still save your document as .fig to make it downloadable. And off course, you can share your files with others.
Figma works on Mac, Windows, Linux and on mobile devices (viewing only). Anyone can just come in and check all the specs: fonts, colors, sizes, distances and many more. And you don’t really need to learn a new tool when trying Figma because it feels and works like Sketch.