If you teach years 5 or 6 in a school in Wales then this app has been written to help you.

You can install it on all the devices you have in school - iPads, Android tablets and Chromebooks. It also runs on all smartphones.

Three sets of questions are fully functional and free. Even if you don't pay to upgrade the app, every child in your class and eventually in your school can benefit.

Also, it's easy for you to let parents know how to find it at home - all they need to do is to type '' into their browser. As well as telling them directly at parents' evenings or when they collect their children, you could put the link on your school's webpages, twitter account or newsletter.

Why not check it out on your own smartphone?