While I don’t use WA as a function of my business it is my preferred personal messaging app. I have been a WA user since early 2013. I don’t trust plain old text messaging (i.e. the green messages if you are an iPhone user). iMessage is great and secure (blue messages on an iPhone) but most of my friends around the world are not iPhone users. I prefer Whats App over Facebook Messenger because Facebook can give that creepy feeling of suggesting contacts that I have no interest in talking to.
Enjoy this guide from iMore. Maybe you will see some features that are new to you.
WhatsApp: Everything you need to know! via iMore – The #1 iPhone, iPad, and iPod touch blog