If you get a call from someone in your contacts list, you will be able to tell as your phone will likely display their caller ID.
However, there's a way for iPhone owners to work out who's calling them before the phone even leaves their pockets. As with other smartphones, you can set specific ringtones for specific contacts, but there's a clever trick that takes this even further.
iPhone users can work out who's calling them, even when their devices are on silent as they can set distinct vibration patterns for individual contacts, writes the Mirror.
