Thank you very much for your feedback.

I found and fixed the issue with closing the timer window while a timer was running. The updated package (0.7.2) is in the repos now.

I actually think the timer was running when you encountered the issue. It's just that during development I decided not to show too much in the way of animations while the timer is running, in order to conserve battery. The timeout which checks the remaining time/expiry runs only every 10 seconds. To give per-second countdown I'd have to reduce this to 1 second, I think. I didn't want to be waking up the CPU every second since I decided this type of measurement didn't need to be high accuracy/resolution.

The only visual feedback (apart from the button icon changing between pause and play) is that the horizontal slider moves as the time counts down, but you'll have to wait 1 minute after starting the timer to see that.

My reasoning was that we're supposed to be focusing on the task at hand, not watching the screen. When I get around to adding an Options dialog I may add the option for more immediate visual feedback from the timer though.

Re the fixed duration/completion date, I actually did design the database with that in mind, and in fact every habit has a start date and end date in the habits table. It's just a case of adding the UI options to manage these. All the database queries use the start date and end date correctly already, so it shouldn't be too much work.

And I still have further additions in mind for the next burst of coding.