Colin, Thanks for the detailed post regarding tracking of discounts. I don't see why this could not be tracked. I can't guarantee it will make it into the system but I see your point and will have to talk with the guys about the best way for us to handle discounts.
Argon, What you say is correct but the timing of the apps availability will vary. GasCubby (iOS) will be launched first (this summer) with the Android version being launched later in the year. You can sign up to beta test from the button on the following page that says "I'm willing to help button on the bottom of this list":
http://www.fuelly.com/gascubby/
I think we only have spots for 100 people to Beta and we have 3,500 who have expressed interest. I'm not sure how we will select our first beta testers but if you are interested, please add your name to the list. We will make sure and email you all when the app update is pushed out.