Cult ­classic Roobarb and Custard is being brought into the digital world as it marks its 40th birthday.

The goofy green dog and his pink feline foe are being turned into interactive appbooks by Brighton publishing and development company Box of Frogs.

Green Wing actress Tamsin Greig, who will voice the three new appbooks, said: “I was a fan of the cartoons as a child (particularly the music) and loved the madcap antics and innocent bravado of the Roobarb hero.”

Box of Frogs is a recent start­up with authors, illustrators, animators, producers and developers working within a Brighton studio.

Chief executive Ben Simpson said: “We are incredibly excited to be working on such an iconic brand.”