NervSounds gives you the power to recreate such noises on your iPhone, allowing you to annoy your enemies by subjecting them to these horrible sounds. Each of the noises is produced through a fun animation.
Unfortunately there are just six sounds included in this free version of NervSounds: blackboard, pistol, mosquito, violin, knuckle cracking, running nose. Choosing the most grating is a difficult one, but I'd have to plump for the dentist drill owing to my aversion to dental surgeries. It also happens to be the most accurate of all the horrid noises included in NervSounds, which is just my luck. The least convincing of the sounds is the balloon rubbing, which, to me anyway, sounded more like flatulence.
There are some notable omissions from NervSounds (crying baby, alarm clock, old lady moaning about something, etc.) but there is a Gold edition of the program available which adds four more sounds.
If you're bored and fancy annoying the people around you for a while, NervSounds is an amusing, if totally pointless, application.