For months I couldn't figure out why events would post to my iOS Calendar app when added from my Chromebook, but events would not post to my Chromebook when added from my iPhone. It hurt my head but I finally figured out that I was using two Gmail accounts. Let me explain. This is for anyone using Google Calendar on their Chromebook, and the stock Calendar app on their iOS device. You can sync your Google Calendar to your Calendar app on your iOS device by following following these steps.
Keeping your calendars synced between multiple devices is a great way to make sure you never miss important events like anniversaries, business meetings, book club events and so on. Your Google Calendar (or Yahoo, etc.) can now easily be added to the Calendar app on your iPhone or iPad. First you will need a Google account. Creating a Google account gives one account access to all Google services such as Gmail, Google Maps, YouTube and so on. Once your account is created, you can then sync your Google Calendar to your iOS device. This will allow you to add events from your computer which will then automatically be added to your iOS Calendar app, and vice versa. Other Google Calendar users will also be able to invite you to add events. Here's how to sync a third-party Calendar to your iOS device: