Spriter can save a scon file that can be imported to AppGameKit and works fine in every animation I have done. (.SCON is actually a JSON file) These work great and allow you to make some fantastic characters with fluid animations in your game. Not to mention explosions and animated clouds or clocks or even an an gry squirrel in my case
DragonBones exports a JSON file and will also export a Spline file which can be loaded directly into AGK. Ive tested a few files exported from Dragonbones and it ooads fine but animations can cause crashes. The model loads fine but animating it requires some manual work with the file.
So...sorry to be bearer of bad news but no importers are actually needed mr Phaelax unless you want to do a special one for Dragonbones? In that case its worth looking at their JSON format or the binary format. Both these Spriter and Spine can be used for skeletal animation in AGK. Its mainly Spriter I use and Spine. Dragon bones looks good and appears to be free!!