Signitic signature is not yet available in Gmail Android. A Google update is planned soon and you will be notified the instant it is available!
This guide is aimed at users who wish to enjoy their Signitic signature on Gmail on their iPhone.
Go to the Gmail application from your iPhone, then click "Settings", then "Signature settings".
Disable the "Mobile Signature" button.
From now on, your beautiful Signitic signature will be integrated when sending emails from your iPhone.
Warning: The signature will no longer be visible when you send emails but it will be added to your email when sent.