If iPhone theft worries you, then PhoneSCREAM may be the app to calm your fears. PhoneSCREAM lets out a series of eardrum-destroying noises in the event the phone is lifted off of a surface. If the standard sounds are not quite annoying enough for you, there is an option to record a voice message of your choice.
PhoneSCREAM works like this: launch the app and then press the pad lock icon. Then, set the iPhone down on a surface. When it is picked up, an "Alert" signal pops up on he screen and whatever alarm sound that was selected sounds. Turning it off is quite simple, however. Just hit the home button to close PhoneSCREAM . The alarm also still works if the phone powers down or is put into standby. In this case, upon pressing the home button and sliding the slider bar, the user is greeted with an Alarm sound and screen instead of a typical page filled with apps.
The question is how useful PhoneSCREAM would be at actually preventing theft. It could catch someone off guard should they try to swipe an iPhone that is just lying on a table. Should they try to start using it quickly the alarm and Alert message could be enough to frighten them into ditching the phone. However, with any bit of user experience a thief may still press the home button as part of an experiment to try and end the noise.
This app could be made more secure if instead of pressing the home button an individual would have to enter some sort of password to regain entry to the phone. As it now stands PhoneSCREAM offers an introductory level of protection, but nothing substantial.
If leaving your iPhone lying on a table or elsewhere in public is a problem, then PhoneSCREAM may make life a bit easier. But for the rest of us who keep a phone in a pocket or purse, a cheap alarm will probably not do the trick.