Before Apple made "Find My iPhone" free for all users, there were quite a few security apps on the App Store designed to protect your personal information and make it possible to find your phone if it were ever stolen. Released around the time that that transition was happening, Alarm Lock was designed to provide extra features for any users concerned about the security of their iPhone. Should your device become lost, it is designed to help you find it fast.
While Alarm Lock has far more features than Find My iPhone at first glance, the interface makes them harder to find and use. However, a video is present, when you start the app, to show you the ropes. It teaches you how to set the password, set a burglar alarm, set up GPS updates, and track your phone should it ever go missing. The setup is fairly straightforward but the recovery process is less so. In fact, we found it complicated to track the phone even with the device in hand. So imagine tracking it with the device already lost.
While Alarm Lock is a useful tool for anyone that wants more direct control over their security measures (including setting an alarm before theft), it has few features that Find My iPhone (a free tool) doesn't already have -- and the interface is just scattered enough to make finding any one piece of information harder than necessary.