If your iPhone passcode is 1234, you might as well disable it. In fact, if it's in the top 10 of the most common iPhone passcodes, it's not really doing you a whole lot of good. To keep your iPhone secure should it fall into the wrong hands, you might want to think about choosing another four-digit code. Better yet, you can create a custom passcode that will make your iPhone much more secure. It's a snap. Here's how:
In Settings > General, choose Passcode Lock. On the next screen, you can choose to turn passcode on and select a four-digit number. Before you tap to Turn Passcode On at the top of the screen, look a few lines below and flip the slider next to Simple Passcode to OFF. Now, when you turn the passcode on, you'll be able to enter a code of any length that can include numbers, letters, and symbols.
As for the enterprising third-party app, Big Brother Camera Security, which collected data from 204,508 passcodes, , claiming it was "surreptitiously harvesting user passwords."