Anzovin Studio has shipped its Onion Skinner plugin for Maya.
The add-on displays ghosted versions of the previous and subsequent frames of an animation, just like in traditional or Flash animation, enabling artists to check poses in context.
The colour, opacity and frame range of the ghost images are all user-controllable, and may be toggled on and off for individual characters or objects in a scene.
Anzovin Onion Skinner is available for Maya 2011 and above on Windows, Mac OS X and Linux. It costs $29.