Do you set the phone to silent / vibrate? Have you missed an important call because of it? If yes, then "interrupt" is for you. Never miss an important call!
= Features =
+ Rings the phone if caller marks the call as important using Interrupt or with =i= message. Your friends can send you a message =i= and then call you to ring your phone even if its in silent mode
+ Detects important calls based on heuristics. Two successive miss calls will make the next call ring even if phone in silent mode
+ VIP contacts that can ring your phone even if silent
+ Blacklist contacts for unwanted phone and messages
+ Highly configurable product
BLOG for more details - http://interruptdroid.blogspot.com