For obvious reasons, freemium releases have a knack for clocking up millions of downloads in quick time.

The latest game to get out of the blocks especially quickly is Nexon's KartRider Rush, which has managed to amass more than 1 million downloads within its first week on the App Store.

In-app appetite

The game, which originally featured on PC and has been played by 200 million players mainly in Korean, China and Taiwan, is free to play, but comes equipped with in-app purchases for either $1.99 or 99c.

The Korean publisher puts its success down to its decision to optimise the experience for iOS play rather than just serving up a straight port.

Players are able to take part in four-way local multiplayer via Bluetooth, suggesting Nexon was keen to target the party game market.

Up next for the title are launches on iPad and Android later in 2011.