For most of us, the days of dedicated alarm clocks are long gone. All you need is your smartphone placed on a bedside table, and you're ready to be woken up the following day. From timers to stopwatches, the clock app on your phone is an essential tool. You'll find no shortage of alarms and timers to choose from on Android, but Google's Clock app makes time management easy, and it's included by default on plenty of devices. The app has finally ticked past the one billion installs mark on the Play Store, and it's showing no signs of slowing down.