@Bengismo,
what AppGameKit can't do ... Spriter files are not support well, and most serious artists use Spine because of the Setup-Pose. Spine can do events like Sprite, but that is not implemented in AGK.
Spine can swap between outfits / skins. And in Spriter you could use another texture Atlas, but both are not supported in AGK.
Spine can do "Add... something to a Skeleton Bone ..." didn't see that in AppGameKit without a huge workaround.
So I don't know, if it must support version 3.7, but the skeleton animation commands are very basic in comparism to let's say "Game Maker Studio 1.4" from 2015
So it is very unusable in AppGameKit, if you can't work with artists, beause you can't trust AppGameKit to play the animations in the correct form. And if the artist uses Spine let's say 3.4 but AppGameKit only supports 3.2, then the animations JSON file can't be loaded.
So for that, it would be great, to update also the playback runtimes in AppGameKit, to be able to use Spine in a better more modern workflow.
And I tried also other programs, but skeleton animations are not working correct in AppGameKit and it is not nice, to be forced, to export only to PNGs or other sprite-animations with massive use of RAM and storage. Texture Atlas in Spriter? Meh ... who needs that
Bounding boxes! Spine supports bounding boxes, but don't know, how to use them in AppGameKit in an easy way.