How to setup Gmail in your iPhone using the Gmail app

Tap the hamburger menu (the three horizontal bars) in the upper-left corner, then tap your name and emailin the upper left.
Select Add account.
Select Google.
This will bring you back at the Add your account screen. Here, enter your Gmail addressand tap Next.
Then, enter your Gmail password and tap Next.
Select Agree on the Terms of Service page.
If you want to add payment information, add your credit card here. Otherwise, just selectNo thanks.
Once finished, you will be back at Accounts in Settings. If you want to see the accounts that you have added, or want to delete any, just tap Google.