What's the catch? Nothing much. It seems you'll have to access the internet via Google's Chrome web browser, so download a copy here (it is free) before your next flight.
I've used Chrome for a year or two now. It is as good a browser as any of the other browsers out there, and can be customized and made even better by adding some extensions to the basic browser.
“Useless” for me, since there’s no Chrome for iPod Touch (and iPhone/iPad).
Please understand that Chrome is NOT required to use the free wifi on these airlines. You can check each airline website for the browsers that CAN be used.