Simply follow the steps below:
Add Your Gmail Account Onto Your iPhone/iPad
1. Tap Settings
2. Tap Accounts & Passwords.
3. Under the Accounts header, tap Add Account...
4. Tap the Gmail option.
5. Enter your Name, Email, Password, and Description for the Gmail account that you've already linked your MyCase account to.
6. You will then be taken to a screen to choose which sections of your Gmail account you'd like to sync with your iPhone/iPad. You can unselect Mail and/or Notes if you'd like, but make sure Calendars is selected. When complete, tap Save in the top-right corner.
Your MyCase calendar will now be synced and available on your iPhone/iPad.