UIKit in Unity

Is it possible to layout UIKit views on top of the Unity3d view?

Yes its possible.
But not with Unity measures neither can you code its behaviour inside of unity.

But Prime31 has created a free plugin that allows you to use UIKit views etc. Its available on the asset store for free and has a rather lengthy thread on the board.

Here is Prime 31’s site.

It’s pretty easy to just call your own custom .mm file for this, too.