This a small project I've worked on this past two weeks, after a few iterations on the design and problems with my messy code (oops), I rebuilt everything from scratch and turned out better than expected.
Timesets features:
POMODORO: Run a custom set of timers to track your time.
STOPWATCH: Simply start it and track the time you are spending on an activity.
Get notifications and/or sounds when you complete a timer.
Option to pause the timer before starting your next task so you can be even more flexible with time.
Simple design with different colors to customize the theme.
Works in mobile, simply add the Web App to your home-screen (some features may not be available).
No tracking, no ads and free.
Works offline too once you've visited the app once.
If you've found a problem or have any feedback please let me know.