QuickWhois 1.4 for iPhone & iPad Price: $0.99 / €0.89 / £0.69

QuickWhois lets you query whois servers to obtain registration status and data about domain names and IP addresses.

The app is all about speed. No need to look up servers or build queries by hand: simply type a domain name or IP address (either v4 or v6) in the search field, tap "Search", and it will automatically discover the correct server for you and, if needed, even contact additional servers to obtain more details.

Queries are added to the list on the main screen, so that you can execute them again with a single tap.
Failed queries are also added, in case the failure was due to a server malfunction or sudden loss of connectivity, allowing you to try again at any time.

Once the results are obtained, they can be copied to the pasteboard or shared via e-mail with a couple more taps.

Please note: the app queries whois servers for domains, not web addresses. Adding "www" in the search field will not work: you have to search for "apple.com" rather than "www.apple.com"!

Screenshots — iPhone / iPod Touch

Screenshots — iPad