What you’ll find in Glyphs v2.4:
— Preliminary Support for Variable Fonts
— Color Fonts
— Interpolation
— Path Editing
— Image Improvements
— Sidebar Filters
— Better Compression for WOFFs
— TrueType Zones
— TrueType Instructor: Deltas, Shortcuts, and more
— New Custom Parameters
— Improved AppleScript support
— UI Improvements and more …
More details on their website —