After the latest security updates made by Google, the Gmail web signature is no longer supported on iOS devices. More information and updates can be found on the Gmail Community page.
Currently, a mobile signature can be used in the Gmail app on iOS and it can be in plain text only. Please follow this guide to create a simple signature you can add to your emails composed in the Gmail app.
Step 1. Create a plain text signature
To create a plain text signature, we recommend adding a new department (for example, named "Plain text signatures for the Gmail app") and choosing the Blank template from our Templates Gallery as the Master template:
Please keep in mind that Plain text signatures are limited to text-only content and do not support the inclusion of images or hyperlinks. We recommend you include only User Info and Contact Info in this signature version.
Step 2. Share signatures for further installation
After you've created and saved your signatures, follow these steps to share them with your colleagues:
2.1. Click on the Deploy button;
2.2. Choose the Send by Email option;
2.3. Select the email addresses of the recipients;
2.4. Hit the Send button to share the signatures for further installation.
The recipients you selected will receive an email containing the signature in their inbox.
Step 3. Installation
3.1. To start the signature installation process, please open the email received using the Gmail app on iPhone/iPad. Once opened, tap the Get your signature button to view it on a browser installed on your device, preferably Safari.
Double-tap on the iPhone/iPad icon in the list of email clients to close the instructions and use the Copy signature button to get your signature ready for use.
Open the Gmail app on your iPhone and navigate to the Main menu
Open Settings and scroll down to the Signature Settings.
Step 7. Remove a transparent image
Enable a default mobile signature and paste the copied signature to the signature's box. You'll notice a transparent image added at the bottom of your signature - please remove it to make sure your signature looks clean: