Proto.io has a great UX, it is easier to use that a lot of other prototyping softwares (e.g. protopie). Think of Proto.io as the Wix for prototyping, it has more flexibility than Marvel but functions slights worse (similar to comparing Wix and Squarespace).

C'est comme InVision, mais hors ligne. Il est très adapté aux étudiants qui souhaitent rapidement essayer des croquis et des maquettes par l'interaction.

Very easy to map out user flows, and Sketch integration is a plus. Being able to visually map out user paths is simple and quick, and adding comments is easy