iScrob

iScrob is a free Last.fm scrobbler and music player app that runs 100% in the background, automatically updating your profile live as you listen to music.

Compatible with all versions of iPhone and iPod touch running iOS 4 or iOS 5.

Free download! Full backgrounding support. Saves offline scrobbles for later when connected. Wi-Fi-only network option to save battery life on the go.* iCloud compatible: scrobble without ever syncing to iTunes! "Love" icon toggle for flagging favorite tracks on Last.fm, Facebook, Twitter. Built-in iPod library access to quickly choose playlists, artists, albums, or songs. Shows song lyrics when available.* No jailbreak necessary! Get it on the app store now.