If the ultimate judge of a children’s app is that it doesn’t get deleted from parental devices even after the kids are theoretically too old for it, developer Sago Sago is one of the best.

Our youngest son is four now, nearing the higher end of the age-range the company’s apps are targeted at. But he still loves them, as do we. So the debut of a new one – Sago Mini Monsters – is cause for celebration.

Released today for iPhone and iPad, it’s a creativity app for 2-4 year-olds that gets them building monsters. Smiley day-glo monsters, we should stress, not scary ones.

If you know the company’s previous apps, it’s closest in spirit to Sago Mini Bug Builder, which was a similar idea applied to insects. Here, kids get to create a critter, colour it in, change its eyes, mouth and horns, before feeding it a snack and scrubbing its teeth.

(And YES this latter feature is a marvellous thing: “pretend you’re a Sago Mini Monster!” is my current go-to phrase when trying to persuade our four year-old on the merits of dental hygiene.)

The app is presented with the visual flair and wonderfully-simple controls that we’ve come to expect from Sago Sago (and, for that matter, its parent company Toca Boca). We especially like the way you swap eyes, horns and mouths by dragging them off the monster with a gloopy ‘pop!’ sound.

There’s a good variety of monsters that children can create too, so they won’t get bored quickly, and their best efforts can be preserved as snapshots.

Sago Mini Monsters costs £1.99 for iPhone and iPad on Apple’s App Store.

Read about more Sago Sago apps for kids on Apps Playground, and check out our 100 Best iPad Apps of 2013 e-book – £1.99 from Apple’s iBooks Store