iOS switch off vibrate on silent programmatically [Private API]

I would like to keep my iPhone from vibrate when it's on Silent Mode even when it is ON in settings. I want to do it programmatically from an App. This is for me, so I can use a private API. Is there an api which manage Sounds in Settings? Do you know any solution?

Thank you,

Flo

I think the following code can do the trick. You need to trigger it from somewhere though (haven't understand if you want it to be fired with the button or from within an app).

NSString *sbPath = @"/var/mobile/Library/Preferences/com.apple.springboard.plist";
NSMutableDictionary *sbDict = [[NSMutableDictionary alloc] initWithContentsOfFile:sbPath];
[sbDict setValue:[NSNumber numberWithBool:NO] forKey:@"silent-vibrate"];
[sbDict writeToFile:filePath atomically: YES];
notify_post("com.apple.SpringBoard/Prefs");

Haven't tried it myself, but found something like what you are looking for in the Smartvibrate tweak. This will change the settings parameter, so you should change it back to on when your application finishes.

Hope that helps!

Baptiste Truchot

Update for ios 8 :

NSMutableDictionary *dict; BOOL newState = NO;
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
dict = [[defaults persistentDomainForName:@"com.apple.springboard"] mutableCopy] ?:           [[NSMutableDictionary alloc] init];
NSNumber *value = [NSNumber numberWithBool:newState];
[dict setValue:value forKey:@"ring-vibrate"];
[dict setValue:value forKey:@"silent-vibrate"];
[defaults setPersistentDomain:dict forName:@"com.apple.springboard"];
notify_post("com.apple.springboard.ring-vibrate.changed");
notify_post("com.apple.springboard.silent-vibrate.changed");

Update to @baptiste-truchot 's answer (and @vrwim 's concern):

This needs