How do I add my logo as an Email Signature to Gmail? (iOS)

You can set up a signature that shows up only for emails you send from the Gmail app.

Note: If you don't create a signature on the Gmail app, your messages will show the Gmail signature you set up on your computer.

Add or change a signature

If you have multiple accounts in the Gmail app, you need to change this setting for each account.

1. Make sure you've downloaded the Gmail app.
2. On your iPhone or iPad, open the Gmail app   
3. Tap the Menu  
4. Scroll to the bottom, then tap Settings
5. Tap your account
6. Tap Signature Settings
7. Switch the Mobile Signature setting on
8. Add or edit your mobile signature
9. To save, tap Back 

You can find more details through the Gmail Help Center Article.