This is an update of an old post, which people still visit regularly, where I described how to get the Facebook / Gmail / email…
Fix Master Sync Disabled in Samsung Galaxy s4, s5, s6 or s7
WhatsApp is a personal messaging system which is owned by Facebook and is primarily used on smartphones.
The service is an effective replacement for both SMS messaging and calls, as voice calls can be made via the service, over the internet, as well as through mobile data, without incurring additional charges.
People also like to send fun messages and gifs, can setup and join groups, and also post pictures and short videos too.