Once you have built a few custom pages of your Composite Application, you'll want to give users an easy way to navigate to those pages.  One quick way is to store those pages in a Document Library and use a List View Web Part to display the pages:

You could then add additional columns to your Document Library to include things like:

1. Descriptions
2. A "Show on home page" field which could be filtered on inside of your LVWP
3. Image/Icon to display an image or icon with your page

You can also update the Quick Launch to include links to the custom pages by building a Header:

And then adding Links:

Which gives you an easy way to get to your custom pages: