The stock clock app tells the time, I mean take a look at the black icon, unlike ios6, in ios7 it says the actual time, with second hand (red) moving and all.
Easily reconnect Bluetooth connected devices by switching on and off airplane mode. Better than switching Bluetooth itself which takes time to reconnect.
In the calendar app; if you need to change the time of an already existing appointment, press on the colored block and you can stretch or reduce the time frame of the appointment without having to edit the appointment.