All are apps to adjust the ring/notification volume based on ambient noise. FoxyRing: Eldest, works, FC occassionally, hasn't been updated in ages, detect every 6-minute (configurable), free. IntelliRing: More functions, "intelligently" detect various situations (based on ambient noise together with proximity sensor and orientation sensors), USD1.99, 30-day eval version available. RingDimmer: Similar to IntelliRing, lacks documentation, USD0.99, free version with limited functions available, users claim battery drain. Volume Tuner: Only works for ring now, only detect before a ring sounds, free. What do you use?