Here's a free app to add to the collection of probably far more useless free apps clogging up your iPhone: RB Song List.
RB Song List is a simple database of all the songs contained in Rock Band games, including Rock Band 3 which released in US today.
It lets you search for songs by title, artist, difficulty or version, and listen to those tracks or buy them on iTunes, with a single click.
Pretty nifty that - no more having to insert different versions of the game searching for a particular song, or sifting through playlists to find a song that easy enough for your rubbish mum to play. And everything is kept up-to-date with monthly updates adding new songs that appear on the online RB store.
Oh, and it's free so what the hell, hey?