The app itself is already available in beta on Android. It is an ethereum client for mobile, and it includes a messenger that uses whisper, a gossip protocol to transmit data (at least for now), which provides darkness and encryption.

The first iteration of Tribute to Talk will be pretty basic with a simple transactional model. A pays B to start talking to B, B can block A at any time. But the smart contract developers are working on more sophisticated schemes for the future.

Here are two related discussions on our discuss forums: Visibilty Stake for Public Chat Room Governance https://discuss.status.im/t/visibilty-stake-for-public-chat-...

PRBS protocol proposal - An incentivized Whisper like protocol for status https://discuss.status.im/t/prbs-protocol-proposal-an-incent...

If you want more precise answers don't hesitate to post there, Ricardo loves to discuss these topics