Sony has released a free Knack companion game for iOS devices via the iTunes store.
The app, titled Knack's Quest, is a tile-matching puzzler in which players can collect items which can be transferred and used in the PS4 launch game.
According to the description, the Knack app is "a simple puzzle game in which you collect 3 or more of the same type of parts. Collecting parts will make Knack grow larger - reach the maximum size within the time limit to clear the stage."
The game also features an Endless mode, in which there's no target other than to wrack up the biggest score you can.
The 'Item Send function', which will link the iOS game to its PS4 counterpart, will be added in "the next software update" at an undisclosed date.
You can download the app free from iTunes.
Knack is a PS4-exclusive platform adventure game directed by PS4 lead system architect (and former Crash Bandicoot dev) Mark Cerny. It will launch alongside the PS4 later this month.
Cerny has described the game as "kind of a mash-up between a Pixar-style animated movie and a character action game". The latest Knack screenshots are here.