No and no. There is as fas as I know, no generic check-in application. Certainly none for any of the US airlines.

A web check-in is called that, because it uses the web site of the airline. Just bookmark the various sites, and use the browser.

Also, there is no good free flight status app. Plenty of very basic apps, but if you want something decent, you'll need to start spending money. I can highly recommend TripDeck or FlightTrack Pro. Both have TripIt integration and push notifactions.

That said - an iPod Touch is going to be relatively useless without a mobile connection, because it'll only gets its updates when connected to WiFi, which means paying for it or hoping for a free connection at the airport.