Vectorify is a powerful and free Maya tool for animators that makes it easy to repath animations
Vectorify
Pickify
Pickify is a powerful selection set tool for Maya that lets you assign a hotkey to selection sets instantly and easily hide or show parts of a geometry
Twosify
Twosify is a free tool by Ehsan Bayat for Maya that allows you to convert your animation to stepped in a non-destructive way
Epic Pen
Epic Pen allows you to draw directly onto your screen, making it perfect for leaving drawovers, notes and visual feedback on animations
Keyframe MP
Keyframe MP is is a compact, yet powerful, media player designed to meet the needs of animators. Features include scrubbing (with audio), single frame stepping, an adjustable playback range and bookmarks. Free Trial available.
Graph Editor Redux
Graph Editor Redux is a redesign of Maya’s curve editor toolset. Not only does it reorganize the classic graph editor functions, it provides new tools that many animators have found extremely helpful in massaging animation performances.
Animator's Resource Kit 