Cron - Cron Calendar.
imgix - Real-time Image Processing. Resize, crop, and process images on the fly, simply by changing their URLs.
zcal - zcal is the fastest way to schedule every meeting for Free and make it personal.
Cloudimage - Cloudimage.io is the easiest way to resize, store, and deliver your images to your customers through a rocket fast CDN.
Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.
Gumlet - Gumlet is an end-to-end video streaming and image delivery platform