There’s quite a lot free patches you can download from Elektron. They managed to hide them quite well on this page: http://www.elektron.se/support-and-downloads
Most third party stuff can be found in this thread: Definitive list of Analog Four patch downloads
Personal favorite is Daren Ager’s “Druma” (for a few bucks) that really opened my eyes for how good the Analog Four is on electronic percussive sounds.