Donte The Calendar - Send calendar invites using phone numbers
Google Calendar - Spend less time managing your day & more time enjoying it
Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.
Mixmax Calendar - The fastest way to schedule meetings with anyone, anywhere
Calendar Screener - Rules to manage your calendar invites.
Clean Google Calendar - Makes Google Calendar look nicer & launches as a desktop app