It depends on if you have a set policy for tracking time. Many companies have 1/4 minimums so you're in the .25 world. We're an 1/8 of an hour company ourselves. That's why you see three decimal places with the task timer.
If you are using the timers in Intervals when applying the time there is a "round up" option. This will keep the applied time in the formatting above.
Regarding widgets, a Mac and PC widget are in the short-term roadmap. We are looking forward to opening up Intervals more for usage without having to be logged into the web interface.