Take Us to Periscope Depth
When you first start up Periscope, you see some colorful cards explaining the basics of the app and how to activate features like your camera, microphone, and location services. I like that Periscope integrates all of this into the app’s tutorial, rather than just throwing a bunch of ugly dialog windows at you.

When I first reviewed Meerkat, I didn’t like how it had you automatically follow everyone you follow on Twitter. Periscope makes following optional, and it  suggests other popular users who you don’t follow on Twitter but may want to follow on the video service. By default, you receive an alert when someone you know on Twitter joins Periscope, and when one of your Periscope pals hosts a new live stream. You can add more friends and tweak your profile by swiping all the way to the right, in the People section.

You can also search for Periscope users without following them on Twitter. For example, if you’d like to watch PCMag’s Periscopes, simply tap the big magnifying-glass icon and search for the Twitter handle @PCMag in the People section of the Periscope app.

The key difference between Periscope and Meerkat is that with Periscope you can save your streams. This becomes immediately obvious from the app’s main page, which shows both live streams and streams that have already ended. Periscope’s main page helpfully shows streams you’ve already watched, featured streams, and streams from the people you follow on Periscope. I really like how it puts the most relevant content up front, though curated themed channels like those on would be a welcome addition, too.

You can find featured Periscope streams from people you don’t follow in the Global tab. Emphasis on global. This section of the app shows a world map with markers for live broadcasts. A quick glance at the available streams shows Periscope users from around the world. Jumping from stream to stream, voyeuristically sitting on the host’s shoulder is an addictive experience.

Through the Periscope
While you broadcast a stream, your screen shows you exactly what your viewers see. Before you start broadcasting, you have the option to toggle your location information, send out a Tweet with a browser link, or host a private session with only select followers. You can also restrict commenting or only allow viewers who also follow you to have a say. It’s a nice way to keep the conversations focused. If someone says something out of line, tap their comment and you can block them.

A recent update to the Twitter iPhone app now converts Periscope links into a live preview in your Twitter feed. Tap it, and the stream will fill your screen and give you the option to open the Periscope app. Once the stream ends, the preview remains animated. It’s a surprisingly dynamic experience, and it goes a long way toward raising the profile of Periscope. But if you, like me, would rather not be subjected to the whims of the masses, just change the iPhone Twitter app settings to never auto-play videos. For now, Periscopes will only play inside Twitter’s iOS app, but the feature is reported to be coming to Android and Web Periscope users soon.

I really like how clean and simple the Periscope app’s interface is, unlike the cramped, cluttered experience on Meerkat. And that ease of use doesn’t come at the price of functionality. For example, double-tapping the screen toggles between the front- and rear-facing cameras, and the Stop Broadcasting button is in a hidden tray you pull down to reveal. Want to switch to landscape mode? Just flip your phone 90 degrees. It’s easy! That said, I’ve occasionally seen landscape streams start out sideways before orienting correctly.

Those watching in the Periscope app have the same clean interface the streams’ hosts enjoy, but with different tools at their disposal. Tapping on the screen makes little hearts appear, and you can tap away to your, ah, heart’s content. I have to admit that, as a host, this is pretty gratifying.

Viewers can also leave comments, which appear as smart little bubbles that disappear after a few seconds. The host can’t type back, and must speak out loud to respond. It’s actually kind of a neat interaction, and it keeps the comments tidy. However, I did notice that on one popular stream comments were locked due to the high number of participants. That’s disappointing, though even positive comments can feel out of control when they fill up the screen. It’s also odd, since there doesn’t seem to be a maximum number of viewers for Periscope streams.

Periscope streams can also be watched live in a Web browser, though Web viewers can’t interact with the host, nor can they see comments or hearts. Watching Periscopes from a browser also requires Flash, which is kind of terrible. I do like that Periscope lets browser viewers toggle between an odd zoomed-in view and a correctly sized, vertically oriented view that mimics what the host sees on his or her iPhone. The Web version of Periscope also shows the most recent stream available for replay, though I would prefer if each stream were embeddable, with its own individual URL

Facebook recently launched its own live-streaming tool called Live, though it is currently not available for all users. Like Periscope, it saves your streams, and lets viewers watch them live on your Facebook page. I haven’t tested this newcomer, but it’s sure to be a strong contender, if it’s ever rolled out to non-celebrities.

You can also delete streams saved to Periscope to prevent people from replaying your streams, but Periscope only displays your most recent stream for later playback in the app and on the Website. If you want to save the streams you create to your phone, you have the option to do that at the conclusion of your Periscope stream. But note that your phone might fill up quickly if you try to save a multi-hour stream. You cannot, however, embed the streams Periscope saves on its servers, nor are Periscopes embedded outside of the iOS Twitter app. Sadly, user comments and hearts aren’t visible in Periscope videos you save to your phone, but they do appear in the videos saved to Periscope online.

Despite the high polish on Periscope, it’s not without problems. It’s annoying that the service only saves the most recent stream, instead of making replays available on my user page. Meerkat can be configured to Tweet out a link to your stream before it begins, giving fans a chance to congregate. Periscope should definitely copy this feature.

I C U
If Periscope had debuted any other day, it would have been views of people’s homes, dogs, and offices. But shortly after Periscope’s release, a building exploded in New York’s East Village. And while there were surely YouTube videos, Tweets, and Vines of the disaster, it was a series of Periscope streams that garnered much attention. And not just one stream; finding multiple angles from Periscope users all around the city was (distressingly) easy to do.

I don’t want to sound hyperbolic, but I’m reminded of the flurry of attention Twitter received during the Arab Spring. Suddenly people understood how powerful the platform could be. When I discovered how many streams I could see of the New York disaster, I think I finally understood why live streaming can be so compelling, and how it might change how we interact online. That’s especially true these days, where bystander cell phone video can make the news, as it did in the tragic case of Eric Garner. In fact, Periscope’s developers have made a point of saying that they see potential for unique journalistic opportunities with their app. With Periscope, we can see the world unfold right now, and then watch it all again later.

Stream Your Life
The big problem with live streams is that, for the most part, life is boring. On the rare occasions when something interesting happens, it’s often over before we can tune in. Periscope neatly solves this problem by saving streams, giving each stream a life outside the moment. This also allows for Periscope’s staff to curate videos in the app, allowing the company to put its best foot forward.

Replayable streams alone would be enough to win out over its main rival, Meerkat, but Periscope doesn’t stop there. It’s highly polished, exceptionally easy to use, and has worked to quickly introduce critical new features, such as limiting comments to followers and highlighting Periscope feeds from your friends. That said, I would like to see Periscope make saved streams embeddable and to copy Meerkat’s scheduling feature, which Tweets out the URL for a livestream before it takes place. Nevertheless, Periscope remains the clear Editors’ Choice for live-streaming iPhone apps.