Available on http://www.rendertom.com and http://www.aescripts.com/slice-it-up/
Workflow is straight forward: select a layer you wish to slice, enter desired value for slices, check / uncheck two checkboxes, select Container Mode and hit Slice it Up. Sit back and watch the magic happen.
After slicing is finished you will see new composition that has Slider Controls attached to it. Parameters like Y Offset / X Shuffle / Z Space are meant to be animated. Choose between linear and randomised offset for those values. Combining them together with Rotation and Expansion will result in great and unique animation.
You have ability to randomise slices right in the GUI at any time. If you don’t like the width of each slice and want to have it different, hit “Randomise: Width”. If randomised position for the slices is not your taste, re-randomise them at any time without loosing your keyframes even after closing / opening the project.