SL SMS helps you create SMS tickets and lets you keep track of them. It also lets you generate a Passbook ticket from a ticket you purchased from SL.
It shows you how many SMS tickets you have send, how much you have paid (in Swedish Kronor). It also lets you easily reuse created tickets so that you can send new once quickly.
Using the Passbook functionality, you can now even easier find your tickets you purchased. Stop searching through your messages, just open Apples Passbook app and use the ticket from there.