Android and iOS Shared Calendar review
All android phones come with some type of calendar software. It's not likely to include an important feature - shared calendar. This feature allows you to view calendars that others share with you. Microsoft Outlook for Windows has this feature built-in.
After searching and testing different MS Exchange / Office 365 / Outlook compatible Android programs, I found one, called 9 Folders, that not only has this feature, works great, and has great reviews, it also syncs Contacts, Memos, and Tasks.
You can try this app for free for two weeks. Then if you want to keep using it, it's a one time fee of $14.99.
Note that the default setting is to not share calendars. To view your shared calendars, tap the menu at the top left, the settings icon (gear) at the bottom right, the account of the calendar under Account Settings, Calendar, then + to Add Shared Calendar.
To view your calendars, tap the menu at the top left, then the second from the left Calendar icon on the bottom.
I've found this program to be very stable, has more features than I had originally imagined, easy to use, and has a great interface.
Here are some of 9 Folders features:
Other servers (IBM Notes Traveler, Groupwise, Kerio, Zimbra, Horde, IceWarp, MDaemon etc) supported Exchange ActiveSync.