Below are some links showing you how to install an HTML email signature in various email clients:

 

Gmail on iOS Devices (iPhones/iPads):
For Gmail on iOS devices, as long as it’s properly installed in Gmail on the web (per above instructions), just make sure that “mobile signature” is turned off in the Gmail app on your iPhone/iPad by going to Settings > Signature Settings > un-tick “Mobile Signature”.

It won’t show up when you’re composing a message on your phone, but it will pull your signature from where you originally installed it in Gmail and send it along with your message.

Gmail on Android Devices: https://youtu.be/OrqF_pOs560

 
 
Outlook on a Mac (OSx): https://youtu.be/nTJAkljxd30
 
Outlook Web App (OWA): https://youtu.be/Eu0R0gM9zlk
 
Outlook Mobile App (iOS/iPhones/iPads only): https://youtu.be/SbU51liJKiA
 
Apple Mail:
 
 
iOS (iPhones/iPads) – https://youtu.be/uWW2PlUMuko
 
 
 
 
GoDaddy Workspace: https://youtu.be/J93hpNg3WEE
 
 
Third-Party Mobile Apps:
 
Spark Mail (iOS/Android) – https://youtu.be/w3-AQcnsEB0
 
Aqua Mail (Android only) – https://www.youtube.com/watch?v=7tBi2_VdnNA