Threema. The Secure Messenger
5,000,000
KakaoTalk : Messenger
100,000,000
imo-International Calls & Chat
1,000,000,000
LINE: Calls & Messages
500,000,000
Telegram
1,000,000,000
Marco Polo - Video Messenger
10,000,000
Messenger
5,000,000,000
100,000,000
TamTam: Messenger, chat, calls
10,000,000