CBeebies show Grandpa in my Pocket has become a firm favourite for children in the UK, as its title character dons his shrinking cap and turns into a (suspiciously agile) teeny-tiny person to get up to all manner of japes.

Now it has a new game for iPhone and iPad: Grandpa in My Pocket Mr Whoops and the Surprise Treasure Hunt. It’s actually the second app based on the show, following last year’s Grandpa in my Pocket Book.

As the title implies, the focus here is on shop-owner Mr Whoops. Well, sort of.

The storyline concerns a treasure hunt around the town, with Grandpa and his grandson Jason having to find a bunch of toys and return them to Mr Whoops’ shop before he returns from the factory.

Judging by the screenshots, this means a ‘hidden objects’ game tailor-made for children (i.e. not as head-achingly difficult as the ones made for grown-ups). It costs £2.99 on the App Store, and runs across iPhone, iPad and iPod touch.