Gmail Email Signature Instructions
To add/modify your email signature in Gmail, launch Gmail in a browser window and click on the gear upper right hand of page and select Settings
Copy your email signature (or just the text) from this page, paste into Gmail Signature, and select Save Changes at bottom of page
The easiest (and in my opinion best) way to view Gmail on your smartphone is to use the Gmail app, available for iPhone and Android. It will add the signature you created above automatically.
If you want to use built-in Mail for iPhone, navigate to the signature you want to use and copy it:
Go to ‘Settings’ on your iPhone, scroll down, click on ‘Mail’ and open ‘Signature’ field at the bottom of a window.
Create a new mail signature if you do not have one already.
Paste the signature and save.