You might want to check out DragonBones.
Both programs are great and very similar. Spriter is reasonably priced, has detailed documentation, and has lots of tutorials to get started right away.
DragonBones is free and has mesh deformation (Spriter doesn't). But the documentation is poor and not a lot of tutorials.
However, IstvÃ¡n SzÃ©p has a DragonBones course on Udemy that is very comprehensive.