Indicator for Whether you've Played Today
Sometimes, I forget whether I've played Duolingo today or not. Sometimes, I play it a little past midnight, so I already have 'tomorrow' covered.
But, I seriously forget. I just wonder if there could be some indicator, to show you haven't played it today.
If you click on "weekly progress" to the right of your tree, you see how many points you got at each day of the past week. The present day is at the most right; if you have at least one coin there, you have practiced.