It's nice. It's not initially clear exactly what it is or how to use it, but I think that would be rather simple to fix. Keep it simple when you start working on the visual front.
It's just such a simple app I think you should be able to sum it up in that first blurb.
And maybe separating the phone# and the PIN would simplify it a bit. something like "Call this number to begin a conference call: XXX-XXX-XXXX. This is your PIN. You will be prompted for this after dialing." Or whatever..
