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.
·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, ...
·Sports (ski, cycling, hiking, climbing).
·Noisy environments (construction, concerts, etc.)