• TalkingTime speaks the time on the hour and/or half-hour. Optional "ding" at :15 and :45.
• "Set and forget". The app only runs during setup so you can do other stuff with your phone, and it won't run down your battery.
• You set the schedule.
• TalkingTime respects the 12 (AM/PM) or 24-hour time setting of your device.
This is the most useful utility app on my iPhone.