Developer Profile Page - is the page, where you can see the Open Exhcange member profile details and all his/her applications.
You can reach it if you click on the publisher name in on the left side of the published app.
Set publisher name in a Name field of the account settings page.
You can introduce descriptions and links which would be placed on the top of the app-list like here:
This can be setup in an account settings page as well. Use markdown to setup the description and links.