Design a sonic for the show (kids only!)

As reported by SFX: following the Abzorbaloff and the Junk TARDIS, Blue Peter offers 6-15-year olds the chance to design a new sonic device for a recurring character (very mild spoilers as to who) to use in a future episode. Cue more we-never-had-this-in-my-day grumbling from old folks like me. :)