Keyframe several different expressions on one property
The Expression Timeline allows you to apply several expressions to a property such that each expression is active only for a certain period of time. Instead of an abrupt change between the expressions you can also smoothly transition from one expression to the next.
Change a few keyframes all others change automagically
Did you ever needed to change a mask or other property with hundreds of keyframes? With KeyTweak, you simply change a few keyframes and all others change automatically "accordingly". Sounds like magic? Go ahead and see yourself...
With Tracker2Mask you can track the movement of masks using the After Effects point tracker. Just track a point and Tracker2Mask moves the entire mask accordingly. You can also track several points for a tracker-assisted rotoscoping workflow.