What is Periscope?
Periscope is Twitter's new live-streaming video app, not to be confused with the recently launched Meerkat, also a live-streaming app. It allows you to watch and broadcast live video from all across the globe, meaning you could switch from watching a peaceful wander across the beaches of Cornwall before switching to a protest in Egypt.
One of the key differences between the two is that Periscope saves the video streams once you are finished, so that anyone can view them for up to 24 hours; Meerkat's live video disappears once you choose to end the broadcast.
Both Meerkat and Periscope are pre-dated by other attempts at live-streaming apps, all of which fell by the wayside. But now, with more open Wi-Fi networks and faster 4G mobile networks than ever before, live streaming looks set to become as regular a part of our lives as Googling and Snapchatting.
How does it work?
Periscope's live feeds can be shot from iPhones and iPads and watched through smartphones, desktops or laptops either through the app or on Twitter's site.
You can watch back recent broadcasts or browse live streams by pressing the TV icon on the bottom left of the screen.
How did it start?
"It may sound crazy, but we wanted to build the closest thing to teleportation. While there are many ways to discover events and places, we realised there is no better way to experience a place right now than through live video. A picture may be worth a thousand words, but live video can take you someplace and show you around." So says the Periscope team on their website. Founded a little over a year ago, Twitter acquired Periscope in January for a reported $100 million.
How can I download it?
In order to shoot video via the app, you need a Twitter account. Once you've downloaded Periscope from the App Store , you're given the option to subscribe to the Periscope broadcasts of those you follow on Twitter. You'll be notified every time one of them starts streaming, and once you're watching a broadcast you can type out a message to the owner and fellow watchers, or send a 'heart' to indicate your approval.
How can I start my own stream?
Before you begin broadcasting, you can choose to limit the audience of what you're about to stream by pressing the people button on the bottom right of the screen. You then tap the shoot icon, enter the title of what you're about to stream and press the Twitter icon to promote the stream via your account.