A BLACKHEATH teenager's hit app has been downloaded 10,000 times - but nobody can solve all its fiendish riddles.

Ben Minett, 17, invented The Riddle Game and put it online with the help of developer BMS Electronics, after spotting a gap in the market.

The Eltham College student's free app provides users with 125 riddles - a different selection for each person - and gives them the incredibly tough task of solving them all.

He explained: "The idea came whilst on a car journey where I thought there should be an app which offered word games, rather than animation, as they would be easier to share with other passengers."

Some of the puzzles have been made up by Ben, while others will be more familiar. But, although game provides hints if you get stuck, nobody has yet managed to crack them all.

He said: "So far no one's completed it.

"I was looking at all the downloads and they come from all over the world. I think it's spread by word of mouth."

This Is Local London: Screenshots of the puzzler

The teenager, who has 12 A* GCSEs to his name and is currently studying mathematics, further mathematics, economics and physics, said he is interested in a future business career.

And he admits to a talent for solving riddles. He said: "I'm quite good with them, my friends always ask me what the answer is."

Visit the App Store to get the game 

Can you crack five of the riddles?

Until I am measured I am not known, yet how you miss me when I have flown. I am...

The more you take, the more you leave behind. They are...

What lives in the corner but travels the world. A...

What always runs but never walks, often murmurs never talks, has a bed but never sleeps, has a mouth but never eats? A....

Feed me and I live, give me drink and I die. I am a...