Tenant app
Phone notifications and announcements
Install the apps on a phone, and write to every tenant in a building.
Both apps install on a phone without an app store: on Android tap Install; on an iPhone use Share, then Add to Home Screen. Then turn on notifications in Settings.
An announcement goes to every tenant living in a property, or in all your properties, who uses the Tenant app: on their home page, as a phone notification and by email. The form tells you how many it reaches.