GPS App on 3GS to point direction to perosnalised locations

People,

I need to use my iPhone 3GS for the following application:

- Enter a number of locations into an app.
- When on-site at a client, I need the app to be able to point me in the direction of any of the personalised locations that I have entered into the iphone.

Essentially, what I need is to see, from a clients' roof, what direction is it to Our Personal location A or Our Personal location B etc.

Does an app with these capabilities exist?

Thanks!

Not that I know of, but there are thousands of APP's.