YONK

Step Motion is a Blender addon for creating stop motion style, frame-by-frame animation. Create, duplicate and add frames while editing and sculpting with hotkeys, use onion skinning, and preview your animation in real time.

Wiggly is a lightweight Blender add-on for creating noise-based, loopable animations using lattices. Auto-size a lattice to your selected object, tune its resolution, add wave animations, and let objects interact with the lattice using physics.