Does one lag more than the other? Are they all free? I am not good enough to text, but would like practice speaking and pronounciation.
If you want to talk with Korean to practice Korean then kakaotalk(this is an app for your phone). That is what korean use the most. You can do a txt chat and send voice messages and call someone like a phone call for free if you use wifi.
If you want to get a chat very quick with communication WhatsApp is a good chat. If you want to talk using micro and camera Skype is excellent, both chats are free.
Good luck.
I dont think Tango is popular since I know nobody uses it around me. :)
Thanks. I will check out Kakaotalk. I am not good enough to text in Korean. Is Tango popular in Korea?