How did people in the past know what time it is? The bell towers told them! (Or a grandfather clock or maybe a cuckoo clock.)
Now you can have your android tell you the time by ringing a bell every 15 minutes and on the top of the hour.
You'll always roughly know what time it is, or that it's getting late.
This application can also use a cuckoo-clock sound or a few other sounds.
* Ability to use system notification sounds