Multitone Appear Lite App
Appear Lite brings paging to smartphones. Able to override silent & DND settings, the app is ideal for sending critical alerts to staff, including security alerts, evacuation notices, major equipment failures and other high-priority messages. It's also a great way to assign tasks to off-site workers.
If all you need is a simple, one-way method of communication which is impossible to ignore, Appear Lite is the app for you.