It is the best app for instant messaging. no other app is even near iit n terms of popularity and quality. it replaced the normal messaging(happy that they tought lesson to those telecom operators as there packs were too expensive). whatsapp has already gained a lot of popularity amogt the world. in each update, we get new features such as increased group size, new emojis etc. whatsapp calling feature is good too on good internet connection. definitely an app to look out for.