Gettysburg Companion, free for Android and Apple from the Times & News Publishing Co., is an app version of a regional magazine. It has a calendar of public events taking place around the historic town of Gettysburg and the hallowed battlefield. The calendar notes, for example, Friday's downtown "First Friday, Gettysburg Style." Also, you'll find lists of tours, farm markets, and wineries and other places to visit in Adams County.
The Gettysburg Companion app has "best of the county" picks for local artists, and coupons and an option to download all of its contents for off-line use.
The free American Experience iPhone app that accompanied this year's The Abolitionists series on PBS provides a rich way to explore the antislavery movement. You can use it to take guided walking tours of Philadelphia, Boston, and other cities to see and hear about places key to the abolitionist story.
An "abolitionist map of America" uses your phone's location service to alert you to relevant landmarks near where you are. And if you know of additional places, you can add them and pin photos to the map.
Cap your July Fourth with a barbecue with the help of an Android-Apple app called Grill-it!, from Sluice L.L.C. The 99-cent app has detailed instructions for cooking great meals on an outdoor grill. There's a function for e-mailing or Facebooking the recipes you like, and a steady stream of new recipes to download by hitting the "Latest" icon.
Revolutions in History by Alex Zchut, free for Apple, provides a sweeping look at history. It describes revolutions, including the American one. The app goes back to the Great Jewish Revolt in the First Century.
Contact Reid Kanaley at email@example.com, 215-854-5114 or @ReidKan.