Do the following to change your email address for iStudiez Pro Cloud Sync account:
1. Sign out from your current Cloud Sync account.
Go to iStudiez Pro > Settings/Preferences > Sync > disable the option.
2 Create your iStudiez Pro data backup.
Go to iStudiez Pro > Data Managing > Create/Send Data backup.
Send the backup to your email address (or save it any other way)
3. Create new account with the email address you would like to use.
Go to iStudiez Pro > Settings/Preferences > Sync > enable the option > tap/click "Create New Account" button.
Follow the instructions on how to register and activate your new account.
4. Open iStudiez Pro data backup you have created earlier (Step 2) and restore the data.
5. Sign into your new Cloud Sync account (using your new account credentials) and sync.