! With iOS 6.1 the problem is fixed!
With the update from iOS5 to iOS6 Apple changed the Captive Network Support, so that the option automatic Login in the WLAN / Wifi options is no longer available. This App simulates this option which means that it removes given SSIDs from automatic login.
It registers a list of wireless network SSIDs with Captive Network Support, thereby assuming responsibility for authenticating with those networks. Typically when a user joins a captive network, Captive Network Support provides a web sheet that allows the user to authenticate with the network. Wlan Aid registers the SSID of the captive network, however, the web sheet is suppressed, and the user can complete authentication in Safari.