Instead of giving you all of the Civil War at once, the History Channel's commemorative app lets the 150-year-old conflict unfold day by day, on a newspaper interface. On April 7, 2012, for example, your iPad will download the April 7, 1862, edition, with news on the Battle of Shiloh and updated casualty counts for both sides.
WIRED "Diary updates" from Lincoln and other leaders. Hi-res maps.
TIRED Daily minutia is a bit much for casual historians. Can't skip ahead to check out "future" events.