Twirlaby: Jewellery Music Box

Unfold your iPhone Duo and the lid lifts, the music plays and a dancer twirls. On any other iPhone, swipe the lid open. Six boxes, from fairy to dinosaur.

On iPhone Duo, your phone becomes the jewellery box.

Closed, its cover screen shows the lid. Start to unfold it and light spills out from underneath. Open it up and the box is open: a dancer rises on her turntable in front of a mirror on the top half of the screen, turning slowly to a tinkling tune, while the jewellery tray waits on the bottom half, folded just like a real box. Close your phone and the music winds down as the lid comes down.

ON ANY OTHER IPHONE Twirlaby works on every iPhone. Swipe up on the lid and it swings open; swipe down from the top, or tap the brass catch, to close it again.

SIX BOXES, SIX DANCERS Swipe the lid sideways to see every box, or tap a charm along the bottom.

• Fairy: rosewood and rose velvet, a ballerina with lilac wings • Ocean: a leaping dolphin, shells and pearls • Space: an astronaut on the moon, planets and rockets • Unicorn: rainbows, a horned tiara and a rearing unicorn • Dinosaur: footprints round the lid, amber and a little green dinosaur • K-Pop: stage lights, a light stick and a dancer in pink

Each box changes everything inside: the wood and velvet, the dancer, the mirror and the jewellery.

MUSIC Six well-loved tunes, played on a music-box comb: Brahms's Lullaby, Swan Lake, Für Elise, Greensleeves, Twinkle, Twinkle, Little Star and the Minuet in G. A different tune plays each time you open the lid.

PLAY WITH THE JEWELLERY Pick up a ring or a necklace and drop it in another compartment; tap a piece to make it sparkle. Each box remembers how you left it.

EVERYTHING INCLUDED All six boxes, their dancers, their jewellery and every tune come with the app. There is nothing more to buy, so little fingers cannot buy anything by accident.

NO ADS, NO ACCOUNTS, NO DATA COLLECTED Twirlaby has no advertising, needs no sign-in and collects nothing about you or your child. It works without an internet connection.