1. Version 2.3 had a bug that resulted in the app crashing under very unusual device conditions (after the app was re-started due to very low available memory). This bug has been fixed. Please update to the current version.
2. The app has been renamed to 12-hour world clock. On the FB page and on the site itself, the 2 names, 12-hour world clock and rotating-cities world clock, are used interchangeably.