Web-app idea: Good Day Bad Day

I have an idea for a very simple web-app called Good Day Bad Day.

1. Login with Twitter or something
2. Each day check back to the website
3. There are two boxes: "Good Day" and "Bad Day"
4. Click one of the boxes to indicate the kind of day you've had
5. Your history of check-ins are presented as a string of red/green squares.

A more advanced implementation (but easier for the user) would involve the following:

1. Create a Twitter account which tweets two messages per day:

• "July 24, 2013: fav this tweet if you had a Good Day"
• "July 24, 2013: fav this tweet if you had a Bad Day"

2. Users could fav the appropriate tweet (they could also change their mind, whichever one they fav'd most recently would be their final selection).
3. Implement tracking using the User-Streams to get instant fav data.

The UI of the page would be super simple. Just a string of red/green squares from previous check-ins, maybe display them in a calendar.

This might be interesting for tracking seasons of life or even project cycles at work.

I think having the binary decision between Good Day and Bad Day would be much simpler than other mood tracking apps that have users select a range of moods. In the end, it seems one either had a good or bad day; I never go to sleep thinking that today was a neutral day.

I might pilot this internally to help track employee happiness.