Looking For After Effects Mid-Movements!

Yo yo, Envato lads and ladies! I’m looking for a special kind of animation, moreso a jerk movement animation. Thing is, I’m looking for it to be mid-transitions, not just enter/exit actions. I’ve purchased the awesome content of Mr. Horse, but I’m looking for small movements, jerks and actions WITHIN the layer rather than just intro/outro transitions. Is this even possible w/ After Effects? As you can tell, I’m more template savvy than After Effects savvy (imagine that!) lol.

Check out the Eggplant colored square movement at :14 into this item below.

Notice how it jerks and spins, then returns. Maybe I should learn about expressions or keyframes and whatnot, but has this product been invented? If it hasn’t how soon before you make it, because I want to purchase that ASAP lol. You can respond here on the thread or at info@yourvisiongd.com if you know of a product, or create it yourself! Thanks awesome authors and 'Vato lads and ladies!