ZCast, from six-person startup Zula, lets you start a live audio recording from your smartphone or computer, broadcast a link to the session through Twitter, and then invite others to join. Listeners can leave comments in real time and broadcasters can reply either via chat or live on the air. The service launches today on iOS and the web.

Unlike Periscope, which lets a single Twitter account broadcast to any number of viewers, Zula wants ZCast to be a collaborative affair much in the same way listeners can call into live radio shows. In other words, ZCast isn't "one to many" broadcasting, but "many to many," says Zula marketing chief Hillel Fuld. He thinks audio rather than live video is a more accessible format for everyday Twitter users. Fuld also feels like podcast production requires a cumbersome amount of time, effort, and expensive equipment, while creators are beholden to companies like Apple for distribution.