Whether your Lightning customizations are ready for prime time or you
just want to give your users a fresh and intuitive navigation experience, you decide when the the new Salesforce mobile app goes
live. After you enable your org, assign the New Salesforce Mobile App user permission to some or
all of your users, as well as yourself. You and your users can still use Salesforce Classic on
Where: This change applies to Lightning Experience in all editions, except Essentials
and Database.com. Available on desktop for orgs that have opted in to the new Salesforce mobile app.
When: The new Salesforce mobile app is available the week of October 14, 2019.