The phone rings once, twice, thrice and then you hang up. Your number pops up in the missed call log at the other end and your intended message has been conveyed. You haven’t spent a penny and yet passed on your message effortlessly. At a time when messaging apps such as WhatsApp, Facebook Messenger and Hike were not invented, the missed call system is what most of us relied on. Be it to convey that you have reached your destination safely or that you need someone to call you back, the free missed call did the job.