WhatsApp is one of the best instant messaging services that has more than one billion users, as of the record of February 2016. Almost all the smartphone users are using WhatsApp since a long time now. The best part of WhatsApp is you can use this instant messaging service for free for as long as you want since they have waived all the charges that were set after one year for each mobile number. After getting acquired by Facebook, WhatsApp has got numerous features. On the other hand, it has tightened the security of the service by launching 128-bit end-to-end encryption for every chat. That makes the IM even better since people were worried about the security. However, now, as the WhatsApp has end-to-end encryption, people are using this tool even more. To harden the security, WhatsApp has recently launched 2-step verification so that only you can use your phone number on your mobile. What is 2-step verification? Two-step verification or two-factor authentication helps user...