Whether you are learning to drive, or an experienced driver it can be important to know your road signs. You can buy books which have all the various road signs, but there are some great applications available so you will always have them close to hand.
US Road Signs 1.0 is a visual dictionary of road signs and features signs from the Manual on Uniform Traffic Control Devices, which is published by the Department of Transport. The application also includes some of the localized signs from different states. This app is free and available for owners of iDevices with iOS 3.1.3 or later.
UK Traffic Signs is also free and is an application that will show you what the signs are, but also test your knowledge. This application is great for people preparing for the DSA theory test, and users can track their progress. iOS 2.2.1 or later is required.
Traffic Tutor not only tells users everything they need to know about US traffic signs, it will also test them as they learn the signs. Owners of iOS devices can find this on the App Store for only $0.99/£0.59. iOS 3.1.3 or later required.