labelVersion.text = [NSString stringWithFormat:@"v%@", [[NSBundle mainBundle] objectForInfoDictionaryKey:(NSString*)kCFBundleVersionKey]]; 

const CFStringRef kCFBundleVersionKey;
  /* The version number of the bundle. For Mac OS 9 style version numbers (for example "2.5.3d5"), */
  /* clients can use CFBundleGetVersionNumber() instead of accessing this key directly since that */
  /* function will properly convert the version string into its compact integer representation. */