Intercom for Android lets you place group calls with other Android and iOS(Infinite iNtercom) devices over Bluetooth and Wifi.

Intercom for Android acts like a simple walkie talkie (two way radio):
·No Internet needed. It only uses local communications.
·Minimum configuration.
·Use volume buttons as push to talk
·Bluetooth LE buttons also supported
·No registration.
·No accounts.
·No buddy list.

Sometimes you can't talk directly to people around you:
·Motorbike communications. Rider-copilot. There are special headsets for all types of helmets.
·Inter vehicle communications (up to 100 meters / 238 feet). Motorbikes, cars, etc.
·Sports (ski, cycling, hiking, climbing).
·Noisy environments (construction, concerts, etc.)