In short, my team has a mobile site and an app in the appstore. We have added the meta tag to show the smart app banner. I saw it and everything worked as expected. Probl
Tap on Settings > General > Usage > wait for a while till the list of the apps appear... >
Show all apps > Safari > Website Data > Remove All Website Data.
I've tried this on iOS 7 with iPhone 5s, and it will show the smart banner back.