The app even allows you to alter the colour of the DS to match the one you own. Games can be played once downloaded and as you increase your scores, more DS colours and secret games become available. There have been complaints about the approval of this game with its resemblance of the Nintendo DS as recently there was another game system rejected access to the App store.
It does look rather similar, if not exactly the same, although we're not sure if it operates in exactly the same way, but its available now and will only set you back a few quid.
Links: Apple iPods, Apple