The company detailed potential uses for the feature on its blog:
You can start a Split within any of your groups, just like you can attach a photo or a location. You bought concert tickets for everyone in the group? Attach a Split and get your money back right away, instead of waiting to get cash in person. Buying a group gift? Attach a Split with the total price, and with each person who chips in, the price per person will go down. Collect your money whenever you’re ready.
Although the person who creates the Split is not subject to any fees, contributors to the Split will have to pay a 4% fee plus $0.99, which covers credit card processing fees and a small GroupMe convenience charge. However, GroupMe is waiving the fees from today, March 7, until the end of SxSW Interactive on March 12.
GroupMe is a universal app that's available in the App Store for free. [Direct Link]