Messaging/Audio communication within the app?

I use the app for multiple club level and nation level events each year for long range rifle. Many of our venues are spread over a large area where it becomes difficult to attend to questions and edits throughout the days on as many as 20 simultaneously running stages of competition. Having either messaging or two-way voice capability that was integral to the app so as to identify easily the stage that we are dealing with or wanting to contact would be incredibly useful. By the first event this year I intend to have a portable course wide local Wi-Fi system that we can use to provide local network between tablets and having a non-cellular comms system would be a huge boon. This would allow comms with a specific stage or all stages depending on the selection made in the master? I.E. the match director can communicate with specifically Stage 4 or potentially all 20 stages in a group notification for potential safety related items. Also the ability for each tablet to mark themselves “cold” or “hot” to confirm receipt of a “cease fire” command and have that status visible from the master?

Have you looked at any existing apps for that?

For example

The disadvantage is having to enter and exit multiple apps. It’s definitely an option, but kinda looking for something a little more task specific.

Not really need to enter or exit. You just switch between apps and messaging apps usually show notifications.

Currently running all Android devices. Would you have a specific app you can recommend?

@Peter_Kneip have you looked at the link I posted earlier? I personally haven’t tried these apps, so your mileage may wary. Though some of those apps are well known.

Here is another a more recent list of apps to try.

PS: on Android (before they changed navigation in Android 10) you can tap the square button at the bottom to see the app history and double tap that button to switch between last two apps.