Versions is currently free to use, and unlike Abstract or Plant, it connects to Github, Bitbucket or Azure Dev Ops rather than using its own cloud infrastructure.
However it's unclear whether it will remain a free, standalone product or will eventually require a paid Sympli account.
Streamlined Teamwork
Work on the same design mockup at the same time without risk of overwriting or losing changes. Maintain full control over what is published to the project and what is being saved for later.
Single Source of Truth
Immediate access to the “latest version” of the design as well as all previous versions.
Be on the Same Page
See all the recent project updates and changes in your dashboard’s activity feed.
Transparent History
Inspect when, why and who made a change through the change set history log and visual difference browser.
Ease of Use
Tight integration into macOS Finder, so transition from your favourite cloud storage is a breeze.
Compatibility
Versions currently supports Sketch files with more formats coming soon.