any other apps needed with photoshop CC

What did you buy?

What do you want to do?

At least you should get Bridge which is always included.

If you have bought other applications too, you should download them.

That will depend on what you want to do. The bare minimum I would install photoshop, bridge, and Acrobat(If included). When you get time and if you happened to purchase the full package, play around with Illustrator and InDesign. Then later on try the rest see what they do, figure out if they can help you. Each one can be uninstalled if you don't want it, so don't worry about having them all installed. As long as you have the room, why not try them.