What appears to be a simple representation of a horizontal sundial is rather more. It quite cleverly shows the dial as it would appear in the sunshine at the local time and indicates local apparent time. It is possible to make your own dial by simply measuring the hour angle and gnomon angle from the screen, and then set up the dial so that it matches the displayed dial! There are few extra features such as changing the latitude and ‘sweeping’ the time during the day to observe the changes. My rating 5/10. However, the app does have a page of links to other websites such as NASS and the British Sundial Society, mathematics sites and a couple of others. Their website www.TestTubeGames.com.

(£0.69p, free Lite version available)