Something has really changed in the last three years for the iPhone to become a household name like it is now. Could anyone imagine then that my gas bill would promote an iPhone app? Or any type of software at all? From a gas company?This is the bill I received in April from British Gas. It promotes right on the back of the envelope their iPhone app: EnergySmart TM. It allows the users to submit the gas meter readings to pay accurately for what you use.