The tutorial I really need

I've done a little reading on Avalon, which has helped to provide some
context.  I am curious to know how you would describe Keel to someone
who was already familiar with Avalon.  How does Keel add value to what
you get with Avalon?

The tutorial that would be really helpful to me right now is one that
would create a simple new application, say "I'm thinking of a number
between 1 and n...", and show how to make use of existing Keel services
like those in app-register.  I'd like to take advantage of the
registration, login, and other account maintenance features provided in
app-register in my own application, but I'm not sure how to structure my
app to utilize what's in app-register.

Along those lines, why is app-register an application and not a service?

Thanks,
Lee Grey
SunTrust Banks, Inc.