Works as expected
Not a slick design, but it does a good job. Calculates the tip on the pre-tax amount, as it should. Allows you to round the tip up or down by hand and back-calculates the tip percentage. Rounds the bill's total up or down with one touch. (The "no" button means "no rounding"; a zero would be a better choice there, to match the single-character style of the plus and minus sign on either side.) The display is portrait only and will not rotate. It may look fine on an iPhone, but on an iPad the display can be read from across the room, with no way to make it more discrete. As such, it looks like some kid's game to anyone who happens to walk by. The developer needs to allow the display to size smaller with the standard "pinch" multi-touch gesture. The free version allows the check to be split among several people, which the description claims is available on the "full version." Also, the "Reset" button should zero the amounts, but it doesn't.