This plugin implements navigator.app.exitApp() on iOS to close your application programmatically. Please be aware that your application may be rejected by Apple when using this plugin.
cordova plugin add com.malves-dev.cordova.exitApp or ionic cordova plugin add https://github.com/malves-dev/iOS-ExitApp.git
The usage is pretty simple. Call navigator.app.exitApp(); to exit the application immediately. Optional you can pass a parameter true || false to ask the user if the really wants to close the application.