FareFair

Requires an iPhone 6 (5.5-inch) or larger, or an iPad.
FareFair is designed to instantly compute how much each party owes in a restaurant. You tell it how many parties there are, and specify the settings for each party, including who is sharing food, alcohol, and extras, and for what percentage is each party responsible (usually 100%). This is perfect for people who do not wish to share the cost of alcoholic beverages. Then you enter the bill total, tax, alcohol, and extras totals. A calculator is included for when the bill doesn't break out the totals. You choose the tip to add, and that's it! FareFair will show the entire bill as well as each party's share. You can save your friends as a group so the next time you'll just enter the numbers from the bill.
FareFair uses several default settings to ease your entry, all of which can be customized to meet your own needs.
Help is available on every screen by tapping the (i) button. Not only does it explain each view's items, but it provides a list of all available functions. It also provides a Quick Start guide.