Linking ToDos to a location is a great idea !
I tested the programm a little and have a few remarks.
- first, I had some problems to sort out how the gui works. I think there are too many fields on the screen. and they are not finger friendly either. setting a due date and time using the scrollbars was only possible with the stylus.
maybe it would be better to put all fields into a scrollable list instead.
(take a look at the original n900 'new task' or 'new event' function to know what I mean).
- setting a reminder by date works well. the alarm even popped up when the program was closed.
- I added a reminder and deleted it. the alarm started although the reminder was deleted.
- how can I change the alarm sound ?
- I didn't get how the reminder screen works. is it supposed to let me set up multiple reminders for one todo ? because everytime I change anything and press the disk icon, a new entry shows up in the bottom of the screen.
- how can I uncheck a Todo that I marked as done by accident ?
everytime I wanted to change the due date and pressed the save icon, the todo was marked as done again.

-and of course the most important question:
when will the main feature (alarm by location) be available ?
;-)

best regards,
chris