I really like this idea, and I even signed up on the forum to give my input.

There are a few things that disturb me, mainly from a UI point of view:
- I can't read the actual times of the appointment I'm drawing, because they are in white. Also, my stylus is over them. So I would suggest another color and maybe a fixed position in a corner.
- I can't find anywhere to distinguish am from pm. I end up drawing appointments that turn out to be 02 AM - 05 AM instead of PM. Am I overlooking something or is only AM possible atm?
- I find it very confusing that the screen remains the same (ie shows the same appointments) if I switch to another day. Could you please make it load the new day automatically?
- Could you please make the + do "next day" instead of next year as suggested by some other people too.


Desired features :
- a line indicating current time. That way I know where I am in the planning..
- a clear difference between AM & PM, eg. different color of clock background and a simple switch (if it's not already there)

As for the calendar syncing: I find it works nicely, most of the time. It does not clear any existing appointments. On the other hand, it doesn't read them either. So reading them would be a great +.

I managed to make a new "calendar" for the todoy, and add the appointments there. Now however, after restarting the app, it says "ongeldig kalenderbestand" which I would translate into english as "invalid calendar file". Note, the todoy calendar is still there and contains all appointments drawn.

Keep up the good work. I really love this.