Unus Tactus is an app available from the Itunes store that is compatible with iPhone 3GS, iPhone 4, iPhone 4S, iPod touch (3rd generation), iPod touch (4th generation) and iPad. It requires iOS 4.2 or later to work. It was developed to help people with cognitive and motor problems to be able to use a cell phone. It allows users to dial the phone by touching a picture from the photo-based phone directory. The pictures are placed on a 4 X4 grid. The instructions for creating the directory are fairly straightforward according to a blog written by Jane Ferrell. There is a large help button visible at all times on the screen that will contact an emergency contact by both phone and email. The app also has an interesting feature reported by Jane Farrell to be very useful for those with cognitive disabilities called a Geofence. This feature allows you to set up a mileage perimeter between 1- 15 miles outside of which the phone cannot wander. If the phone goes outside of the perimeter it signals the owner that a message will be sent to the person’s emergency contact with a map of where the phone is located. This feature could be useful, especially for those who wander.