Skype is a renowned global VoIP and internet calling software.
Founded in 2007, Tumblr is the world's largest microblogging platform and the pioneer of its kind.
A global mobile messaging app owned by Facebook.
YouTube is the world's largest video website.
The world's second-largest social networking site
KakaoTalk is the most popular social messaging app in South Korea.
The world's largest online comprehensive community
