Grab Mumble from and add as a server in it!
If the server is down try downloading it directly through this link (Windows).
For Android there's Mumla.

Then to connect to my server:
Server -> Connect -> Add New
Port: 64738 (default)
Username: Pick_one
Label: Pick_again

The default mic setting is voice detection, to just talk at all the times:
Configure -> Settings -> Audio input -> Transmit=Continuous

There's an experimental web version, but it doesn't work good at all.