WeChat, LINE, KakaoTalk, Kik, Viper, Facebook, Whatsapp, Google Hangouts, Pretty much the top of the messaging apps atm but only WeChat actually has a working platform for discovering apps.. LINE and KakaoTalk are following after WeChat and others will follow. I dont think the app store will never die but they just need to incorporate more innovative ways to make finding apps easier. The only reason why the apps of the messaging apps are more downloaded by average is that the selection of apps is much much smaller than the app store.