Use Flow Builder to Send Custom Notifications
Where: This change applies to Lightning Experience in Essentials, Professional, Enterprise, Performance, Unlimited, and Developer editions. You can send notifications to desktop users in Lightning Experience and Salesforce Classic in all editions and to mobile users in the current Salesforce mobile app in all editions, except Database.com, and the new Salesforce mobile app in all editions, except Essentials and Database.com. You can also send notifications to users in Mobile Publisher apps for an extra cost.
How: To learn more, see Send Custom Notifications with Flow Builder.