New features:
- The app now rings the system alarm sound when a timer completes
- Clicking the timer clock now shows the current session count
- The app can now stay in the background and the timer keeps running even when the app is closed
- New notification buttons to control the timer without opening the app

Fixes:
- Current elapsed time is now saved in the stats when the app is closed while a timer is running
- Live Updates/Now Bar now shows precisely how much time is remaining (in seconds)