1. Open https://www.gmail.com, open any email.
2. Click the add-on sidebar, search ‘Simple Mobile CRM’ from G Suite marketplace, and click ‘Install’.
Alternatively, you may directly install from G Suite Marketplace:
3. Click the CRM icon (with orange S), and sign into CRM.
1. Install Gmail Add-on from desktop browser first (see above)
2. open the official Gmail mobile app in mobile device
3. click into any email
4. click the CRM icon at the bottom of email
The notes for all platforms are linked up, you could always write a note in one platform, and read it from another platform.