This iPhone app calculates the tip and grand total from information in your restaurant bill. It minimizes the number of taps to get a result.
You are in a restaurant and you have been presented with the bill. It is time to figure out the tip and you would rather not have to "do the math". Your phone comes with a calculator app so you could do the following. Enter the subtotal excluding tax from the bill, multiply by your preferred tip rate, and add the result to the total amount from the bill.
Let’s count taps. You would have to enter three numbers each with decimal points and three operators (*, +, =) to get the desired result. Howerver, if the tax rate and your preferred tip rate are known from previous bills, then only one number without the decimal point needs to be entered and one additional tap displays all the information you need to pay the bill. That is the essense of this app. Enter the digits for one number then get the result.