Button for Google Calendar™ - See your daily schedule and join meetings in one-click.
Reboot - It's okay to take a break
Calndr.link - Dead simple & free add to calendar links + API
Tabwave - Replace your new tab with a mindful productive app
Add-to-Calendar Button Generator - This open source projects lets everybody create amazing buttons, where users can add events to their calendars.
Stretch From Home - Illustrated stretching routines for your home office