We have two apps appropriate to the holiday season from the US Government today for shipping and travel.
One is a very useful app from the US Postal Service. It uses location services to find your nearest post office, and once you have found it, the hours and services offered there. It also shows all the collection boxes in your area and the pick up times. You can also track a package and look up zip codes. One thing that would be nice would be a postage calculator. Maybe in a future version. At least they give you a link to usps.com so you could look up postage rates there.
The other app is from the TSA. It falls short on the wait time feature, since it relies on users to report the wait times. Other than that, it is a nice handy interface with a "Can I Bring" look up, and a handy travel guide. It also includes a US Aiport status map. So while there is room for improvement, if you fly it is nice to keep this one on the phone.