-Adjust individual people's total by adding or removing an extra amount. (ex: 'Bob had one extra beer, so add $6 to his total)
-Override and lock a person's total and recalculate other people's totals accordingly. (ex: 'Joe is feeling generous, so he is giving $50')
-Change a value and see how it affects the other fields. (ex: 'If I give a $5 tip, how much does that make in percentage?')
-Round up or down. (ex: 'If everybody gives $20, how much tip does that make?')
Split it! works better with large screens, like the HTC EVO.