There is no point in opening multiple threads about the same thing. Your previous thread was ignored, as was the SO post (http://stackoverflow.com/questions/42878818/natvive-script-app-not-running-only-shows-a-splash-screen) most likely for the lack of more information about your setup.
What emulator/device are you using? API Level, architecture, is it native or Genymotion one?
What versions of
tns-ios are you working with?
Is there any logging in the console?
What about the device's log? - Run
adb logcat in your cmd/terminal and do share if there is anything suspicious.
Have you made any changes to the application? How can we go about attempting to reproduce your problem?