This is nice. Clear and straight to the point. There's one thing that could be improved from the user's engagement perspective: when I created a goal and later created an user account, the goal has been cleared.
Bug report: On Firefox dev edition with the goal "Test the software 3 Times in 14 days" I obtain 2 big non scrollable boxes. Even when I complete the goal, I only see these 2 boxes (now green).
For context, the 4 disciplines of execution are
1. Create a BHAG
2. Create lead measures (The GRID GOAL)
3. Track your progress (The GRID GOAL TRACKER)
4. Accountability
This is awesome! I have been thinking about building something like this for a long time. Good thing I don't need to.
The simple goal and counting the days is something I've been doing for years, but on paper and calendars. This is so much simpler, it feels more right. I really like the KISS approach and look here.
One UX factor to point out: I lost my data after signing up for the first time. That sucked.
Otherwise... Thank you, please keep building this, and if you're looking for feedback, I'm here to give it.