Presidents Challenge is a fun and diverting way to memorize the names of the presidents of the United States in order. This app can be used in middle school social studies classes. The child can either choose to do time periods/ eras at a time or try to do the entire list. Each president includes a picture and a little background information about them. It shows a blank timeline and the child can drag a picture of the president to the correct time period and if it is correct it will stay in the correct spot. This app requires iOS 6.0 or later, and the app is free.