I use fb messenger and that's it. In terms of our country, I guess fb, instagram, snapchat, discord, and twitter are the most popular - so basically any popular social app.
So I know Discord is gaining popularity, but idk if it's that widely used since it's catered to gamers mainly. I'd say Facebook Messenger, Twitter, Instagram, Snapchat, and I'm pretty sure for a lot more people Skype is still the go to and not Discord. I could be wrong though.