Newton, by Motion Boutique is a really cool physics engine specifically designed for After Effects. This means you can set real-world rules such as gravity, friction, weight, etc, and have Newton simulate a correctly-behaving animation. This opens up endless possibilities for motion graphics resulting in unique & distinct motion, especially when combined with typography.
Newton works by providing a unique composition timeline of it’s own where you can specify rules and assign physical properties to each object. Newton uses object masks to calculate motion and collision so every object must have a mask. In one of my examples, a cannonball destroys a pillar. The cannonball is a circular mask whereas the pillar has been pre-shattered using multiple masks. The setup for simulations can take some time to create all these masks but the intricately animated payoff is quite worth it.