Just a question and perhaps an observation about your iPhone app....
I'm not sure that I understand why you elected to round the bill when making an entry - "no cents". The issue is of course that the total is therefore inaccurate and does not serve as a final check when totaling the meal charge and tip, as on a credit charge slip. I do understand "rounding" and typically "round" the tip in order to achieve a final payment that has "no cents" - you might consider that as an option vs rounding the charge.
Best regards,
JT