A father who struggled to get his children to learn their times tables has created a chart-topping iPhone app to make maths fun.

Ian Knapp, 36, of Wilman Road, Tunbridge Wells, struggled to find exciting games to make learning tables enjoyable for his daughter, 10, and seven-year-old son.

So he decided to design one himself!

It is called Squeebles Times Tables and is based around the nasty Maths Monster, who has taken friendly Squeebles as his prisoners.

The player's job is to help rescue them by answering multiplication questions.

Ian believes the colourful characters and engaging storyline has improved his children's maths abilities.

He said: "My son is using the app and it really helps him as it makes the learning a bit more of a fun experience.

"I think children are more excited by the idea of using technology and it’s really effective on an educational level because they want to get involved with it."

The game has been so effective it has topped the education app charts in Australia and has reached the top 10 in the UK.

Ian added: "I've had emails from all over the world. One woman said she's having a competition with her son when using the app, so it's fun for parents to get brushed up with their times tables as well."

Ian has now quit his 10-year role at a local web design company to create more education apps.