"UP Steam" is an app for Apple products that's free from Union Pacific. It lets users track UP's steam locomotives and sends an alert if a locomotive is within 50 miles of the app user, among other things. "Historic trains and new technology ... now that's cool!" writes Gregory Vaughn. Meanwhile, on Wednesday, Union Pacific's #844 steam engine carried Civil War re-enactors and cannons to a re-enactment in Arkansas of the Battle of Shiloh, which took place in Tennessee 150 years ago. The #844 locomotive is traveling through Arkansas as part of the railroad’s 150th anniversary celebration.