It is an intercom app (transceiver app).
You can have a conversation between iPhone connected to WiFi.
Features
・ One-to-many call
・ Display of the other party's name
・ Bluetooth headset support
・ Automatic call can be started by detecting voice
・ Voice level adjustment
・ Supports call start sound
This app is a feature-cut Lite version of MyIntercomPro.
For business use, I recommend MyIntercomPro.