It is based on the nCine, meaning it is coded in C++, it uses ImGui, and it would potentially run on all the engine supported platforms: Linux, Windows, macOS, Android and Emscripten.
At the moment you can download a demo for Windows and macOS.
It has no limitations, you can find it on Itch.io.
Some of the tool features are:
- Parent-child relations between sprites for advanced transformations
- You can create animation groups and play them in parallel or sequentially
- Unlimited canvas size with custom background color
- Tuneable shift, scale and speed for animations
- Multiple easing curves and loop modes
- Export frames as single images or as a spritesheet
- Use the mouse to select a rectangular region of a texture for your sprite
- Use the mouse to set the anchor point for grid deformation animations
- Native version for Windows and macOS
- Coded in C++ for maximum performance and efficient memory use
Have a look at this video for an example of what it can do: https://www.youtube.com/watch?v=iqxX3VTt39o