I am trying to incorporate some unilateral exercises in my workout to balance my abs and left side a little more. What are some good unilateral exercises that mainly target the abs?

The rectus abdominus is one muscle and doesn't have a left or right side. Hate to say it, but your genetics plays a part at how uneven they are. That, and make sure you're using proper technique when working out.

Yup, all genetics bro.