This is all doable directly in Blender without any plugins and other apps.
The COA_Tolls addons seems to be only for rendered animations and doesn't work with BGE. I am 100% able to do the same thing directly inside blender with simple flat geometry, shape keys and armatures.
There is also a sprite addon (BGE sprite addon) sold on the blender market for 2D animated textures, I bought it, but unfortunately, it keeps crashing on me every time I use more then 1 animated textures, so I don't use it and I always find a way to make it work without any of these addons (I also messaged the addon creator which is that timster and I never got a reply).
So even if you cannot implement any of these, its still doable. If there is a way to offset UVs based on events then you can most likely animate sprite sheet or 2D textures. For Cutout style, then simple poly geometry with shadless material and transparency and a good armature and you have the same things that you'd find in COA Tools, Spline or even DragonBones.