If you're too deep into your food coma to adequately calculate how much each party owes for the bill, tap open Tip Calculator. The free app, like others in its class, is simple, but rapidly breaks down the total each diner owes. Thankfully, this tip calculator requires that you only type in the number of people and the total bill; then select a preset tip percentage or add your own. Tip Calculator reads out the tip amount, the total bill, and how much each diner owes. Having the app remember your usual tip setting between sessions would improve it, as would the ability to add your own present tip amount--say if 18 percent is your usual rate, instead of the 15 or 20 percent suggestions.