Credit to chrome extension Ponder "https://github.com/thatjpcsguy/ponder", greatly inspired.

CalHack2015! DayCountDown chrome extension! Basic Functionality: countdown; every hour there would be a random video poping up to show people take a break and follow the exercise;

To use:

https://chrome.google.com/webstore/detail/daycountdown/gldjpdjepgkghlcbfmhgflhhefipahcb

Or

1. Go to chrome setting; Click on extension on the left side.
2. Enable developer mode.
3. Load unpacked extension from the path you git clone the extension to.