- Is your goal to have access to the contacts from each Gmail account, but to keep the contacts from each account separate?
- In this situation, I would suggest syncing your primary Gmail account with iPhone using this app, which will bring in both your contacts and groups. Add any additional Gmail accounts by going to your iPhone Settings > Accounts & Passwords > Add Account.
- The accounts you add to your iPhone Settings will not have groups, but the contacts in those accounts will be kept separate from any other accounts.
- Otherwise, if your goal is to create a 3-way sync, with the same contacts in both Gmail accounts and your iPhone, follow these instructions:
To create a 3-way sync, I would suggest syncing your 1st Gmail account with iPhone using this app, and your 2nd Gmail account using this app's sister product ("Contacts Sync for Google Gmail" or "Synctastic").
Alternatively, if you have multiple iOS devices such an iPhone and iPad, you can install this app on each of your devices at no additional charge, and sync your primary Gmail account with iCloud from your primary iOS device, and your 2nd Gmail account with iCloud from your other device.
Alternatively, you can toggle between Gmail accounts from this app, and sync each one individually.
Download Contacts Sync for Google Gmail: https://itunes.apple.com/us/app/contacts-sync-for-google-gmail/id454390333?mt=8
Download Synctastic for Google: https://itunes.apple.com/us/app/synctastic-for-google-sync/id686378579?mt=8