If you're looking for an awesome 2D animation software for rigged characters, i can highly recommend Moho. Funnily, they just recently added gltf/glb export and i tried importing it in Construct and it works great!
mohoanimation.com
I'm not being paid by them but i did a webinar for them a while back and have a couple of tutorials on my Youtube channel. Really excited about the new import possibilities of Construct and it's not even because of 3D :D
Unlike Spine, Moho allows for both bitmap AND Vector rigs and comes with vector drawing tools. It's been used in film and TV for decades, is relatively easy to learn and has a great community. The price is fair too, being a one-off payment.
Really great for me as an animator who uses the software that i can now use it for games! Thanks Scirra!