I discussed chat/file sharing features yesterday with CoinViLLE devs yesterday. We can definitely do something but hands are full right now as we are experimenting on new features. I will look into TOX layout with them today.
Another feature to consider: random chat.
Think chatroulette with built-in tipping.
Or, people could even charge to accept your call. For instance, if I were a Linux expert and you wanted help with a Linux problem you could call me on Viorcoin but it won't ring at my end unless you deposit 50 vior first.