best way to inform the user about newly released application.? iPhone sdk

I j开发者_运维技巧ust want to know that how we can inform end users who are using iPhone app that new version of this iPhone app is now available on app store and specially when we have not coded earlier iPhone app without being considering this functionality.

I don't see a way to do this other than to rely on the App Store app on the device to notify the fact that an update is available for an installed app given that you haven't included any functionality to check for an update yourself.