Vimcal - Vimcal is the world’s fastest calendar, beautifully designed for people who work remotely and live in their calendars.
Clean Google Calendar - Makes Google Calendar look nicer & launches as a desktop app
Add to Calendar Link Generator - Create buttons for Google Calendar, Office 365 and Apple Cal
Plan - Plan is a better way to organize.
Calndr.link - Dead simple & free add to calendar links + API
Digital inspiration - Digital Inspiration is a popular how-to website that covers computer software, mobile apps, video...