For my day job I work on a Calendar application. We provide a CalDav service for customers to access their Calendar data. While it can get tricky to support all the variations, it's a solid standard that makes integration really easy.

One problem we have is that Android doesn't natively support CalDav, so we can't integrate with the built-in Android calendar like we can with iOS's calendar.

For those that work with calendars, CalDav is a well documented standard for sharing calendar data. It robustly handles all the use cases that we've been able to think of (including edge cases).

It's disappointing to hear that Google will discontinue the service. I'm sure lots of iOS and Mac users use the CalDav sync to natively sync their Google Calendar to their devices. How will users of native apps be able to get their calendar now?