WhatsApp is mostly used as the messaging app in this country. It's pretty crucial for business too, and I get a lot of my clients and students whatsapping me for appointments.
I prefer Discord and Google Hangouts. I only use Snapchat and LINE because I have friends / chatrooms that I'm in that are exclusively located on those apps.
I've never heard of Telegram. But I used to use Line a lot for messaging and Line Play. I've kinda abandoned it for snapchat and discord these days though.