There are hundreds of IM (Instant Messenger) and VoIP services available today but not all of those are as much popular as WhatsApp
Facebook Messenger
Facebook Messenger is a standalone app that lets users chat with friends and family without having to access Facebook itself.
Snapchat
The feature that made Snapchat popular overnight is its self-destruction of those videos and pictures.
WeChat is a well known messaging app which is direct competitor of WhatsApp.
TInstagram is a popular social network and social app available for almost all mobile operating systems we use today, that include iOS, Android, Windows Phone, BlackBerry and many others.
Line
LINE is a well known VoIP and IM service that allows users to make audio calls and send messages to their friends all over the globe.
Opera Mini
Opera Mini Browser is around us for more than 20 years and it is the second oldest web browser in the world. It is also considered the third most popular and widely used browser after Mozilla Firefox and Google Chrome.
Fortnite
Fortnite is a multi platform co-op game developed by Epic Games studios, which quickly became number one game of 2018. It keeps growing in popularity on ALL the platforms and smash any records.
Skype
Skype does not need an introduction as this is one of the most popular IM and VoIP services available today.
Dropbox
Dropbox is a popular cloud storage provider available today; although Dropbox has been facing tough competition from other similar apps and services like Google Drive and OneDrive but it still managed to hold the firm position