Take a group photo from the iPhone can be a really complicated if you do not have the appropriate applications. One is LED Photo Timer, an application that lets you set a timer for 5, 10 or 15 seconds to take a picture.
Once you start the countdown, the LED built into the iPhone iPhone 4 and 4S will start flashing. The blink rate will be greater the shorter the time left to finish the timer. By these notifications light that we know the rush to incorporate into the snapshot.
Photo Timer LED notifications also has hearing and allows us to take a photo with flash or without.
The price of LED Photo Timer is 0.79 euros. You can also try the free version is exactly the same features but takes us out with a resolution pictures pretty bad.