1. The page saves EVERYTHING (timers, options, etc.) to the browser's local storage in "real time". This means you can close the page, close your browser, shut down your computer, whatever, and everything will be saved for you to return to the next time you open the page.

2. A timer that is running will continue to time even when the page isn't open. This means you could start a timer, close the page (or even shut down your computer), leave for 2 hours, come back, pull up the page again, and the timer will have captured the 2 hours you were gone.

3. You can increment or decrement a timer by 15 minutes per click by holding down the Control key when clicking the +1/-1 buttons, or by 1 hour per click by holding down Shift.

4. You can also manually edit a paused timer by double-clicking on its time and typing a new value in hh:mm:ss format (or just hh:mm).

5. The cells for Notes will automatically adjust their vertical size to accommodate all text in them as you type (see here for the source of this nifty javascript written by Jack Moore).