How to implement plugin into IntelliJ interface?

I would like my intellij plugin to become part of the intellij layout itself. I believe using extensions is the way to go however I don't understand how I may be able to add buttons, create a new panel, etc. 

My goal is similar to how version control has its own panel and there are github buttons. I would like to know if this is possible and how I might be able to do this.

Any help would be greatly appreciated, thanks!