Mariana Walkie Talkie is an application that allows you to connect two Android devices (such as smartphones or tablet) on the same local network, it is Wi-Fi or Bluetooth. To allow the connection between two devices, the latter should not deviate more than a certain distance (with Wi-Fi the maximum distance that is supported by it, same thing with the Bluetooth).
Mariana is really easy, intuitive and immediate. It is designed to allow anyone to instantly understand how to connect two Android devices without having to read some online guide.
Mariana also includes two ways to speak: PTT and CTT.
Tested on the Vodafone Smart Speed 6 and Samsung Galaxy Trend Lite.