Castro: Is the Latest the Greatest in Podcast Clients?

The field of podcast apps is quickly becoming crowded: Apple’s own app, Pocket Casts, Instacast, Downcast, and soon to be Marco Arment’s Downcast. Can there be room for yet another client in a category that is difficult to differentiate in?

The answer to that question comes in Castro, and it is overwhelmingly “yes.” Castro will, for many, be the de facto podcast client from this point forward.

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Is There Room for Another Podcast App?

With iOS 7 came the expected deluge of app updates. Almost every major podcast client saw a major redesign or rewrite. The result is a category that is highly competitive: even small features or design flaws can knock a particular app out of favor among users. While each app has its own set of strengths, they all have specific features in common.

This is the primary screen of Castro. From here, you can access settings on a per-episode basis.

This is the primary screen of Castro. From here, you can access settings on a per-episode basis.

Every one of these apps has the ability to play audio podcasts. You can download a podcast and listen to it later on all of them, and most of the current crop of podcasts apps allows you to stream audio.

That is, essentially, what a podcast app must do. The difference lies in the way each of these apps goes about accomplishing these tasks, and what features they offer to make these tasks more streamlined.

It is in this way that Castro makes itself useful. While other apps have been updated for iOS 7, Castro is obviously built for Apple’s latest platform. It uses the necessary background APIs to automatically download new episodes by default. Gestures and typography dominate the interaction method, and even the trendy circular photos found within Apple’s own messages are here.


Simplicity is obviously a goal with Castro’s design, and the same can be found within its feature set. While other podcast clients have features like cross-platform sync and importing/exporting via OPML, Castro focuses on the iPhone.


The episode screen also shows a description of the podcast, as well as a list of all available episodes.

I like it. My previous podcast client of choice was Pocket Casts, which is an incredibly powerful app with a bunch of features that I don’t actually use. My needs are simple, and I suspect that most podcast listeners have similar requirements for such an app.

There two omissions that I do miss. Castro does not support video podcasts. These podcasts are nowhere near as possible as their audio counterparts, though the rest of the podcast client lineup does support these programs. Fans of TWiT, take note: you won’t be able to watch your “video netcasts.” If you have subscribed to a video feed, the app simply plays the audio stream instead. I would imagine this to be rectified in a future update, but that’s just speculation: the app developers haven’t commented on any future updates.

The "now playing" screen is focused not on the album art, but on show notes.

The “now playing” screen is focused not on the album art, but on show notes.

The second issue is perhaps more troubling. Pocket Casts, more than any other podcast client, prides itself on its speed. Specifically, the developers behind Pocket Casts have made it a point to make refreshing the app to search for the latest podcast episodes as quick as possible. This dedication to speed has required a backend server infrastructure for Pocket Casts that no other client has been able to match.

That trend continues with Castro, which is noticeably slower in finding new episodes than Pocket Casts. For users who like to listen to a program as quickly as possible, this could be a major problem.

By default, Castro doesn’t allow you to download podcasts over a cellular connection. This can be changed in the app’s settings, which are located within the system settings instead of within the app. This is a relatively annoying design choice, but it isn’t the end of the world.

Streaming! It's a beautiful, beautiful thing.

Streaming! It’s a beautiful, beautiful thing.

I would also like to give accolades to the developers of Castro for including the ability to stream audio. There has been some discussion among developers and podcasters, particularly after prominent iOS developer Marco Arment announced that his app would not include a streaming component in its first version, that streaming audio for podcasts isn’t necessary anymore. On the contrary, I find streaming audio to be significantly more efficient — it means that I only download the episodes that I actually listen to. After I have finished listening to the episode, the cache is automatically deleted. Overall, I find streaming audio to be simpler than downloading it and then dealing with the leftover files. Again, it’s a small touch, but I’m glad that Castro includes it.

Using Castro

For many, Castro will be their most-used app. That’s a good thing: the app has been optimized to allow users to move around it with ease, once you have the design principles down.

Upon first opening Castro, I was confused. After years of using Pocket Casts and, before that, the native music app for podcasts, I wasn’t expecting the simplicity of Castro.

Castro has two tabs which are self-evident: podcasts displays what shows you are subscribed to, and episodes shows individual programs in chronological order.

To scrub through an episode, you just begin swiping at the bottom. While not entirely discoverable, it is easily the best implementation of a scrubber I've seen.

To scrub through an episode, you just swipe at the bottom. While not entirely discoverable, it is easily the best implementation of a scrubber I’ve seen.

Subscribing to podcasts is simple: just tap the plus button and begin searching for shows. There is no list of popular shows, or the most-downloaded programs; users are expected to know at least something about their favorite shows going in to the app. This stark simplicity is at odds with other apps, like Pocket Casts, which makes it easy to find and add new podcasts to the library. It highlights the fact that Castro just isn’t as welcoming for new users or beginners.

Navigating the UI is a crash course in gestures. When in doubt, swipe somewhere — an action is almost always possible by swiping. I do have some mild critiques about the UI not being immediately navigable, though that may just be part of iOS 7’s design language for such apps. The developers do try and place arrows in certain places after swipes to highlight that an action is, indeed, possible.

There are no app-wide settings. Instead, the settings are done on per-podcast basis, and are therefore accessible inside each show. From there, you can unsubscribe from the show, toggle auto-downloads, and activate “News Mode” (which I suggest, as it will delete older episodes when a new one is available, thus keeping the app from using too much storage).

The options for each podcast subscription help to make the app feel more powerful than its interface would suggest.

The options for each podcast subscription help to make the app feel more powerful than its interface would suggest.

You can also toggle playback speed. There are five options: Slowest, slow, normal, fast, and fastest. Podcast producers would greatly prefer you to use normal speed. For those who want to power through episodes, the fast option offers a good balance between speed and quality, though I still prefer the normal speed for almost every show.

The playing screen is utterly fantastic. Show notes, where applicable, are displayed front-and-center — the album artwork presents the glazed-over backdrop. Even better is the scrubber, which is the best in its class. It’s a brilliant piece of design work and user-experience engineering. It’s so good, in fact, that I want Apple to adopt it in iOS 8, because it beats Apple’s option to a pulp in every way possible. It’s the little touches, guys.


The golden age of podcast clients is upon us. iOS 7 has breathed new life into the market, and the onslaught of quality shows keeps it afloat.

As such, Castro has a hard time proving that it is better. At $2.99, its price is comparable with other clients. It does have a shorter feature list, even though it does hit almost all of the required checkboxes. What I love about the app is that it truly feels like an app for iOS 7. While other apps — Pocket Casts, I mean you — have the features, Castro has removed the unnecessary features and UI cruft, and focuses on the simple act of finding, queuing up, and ultimately listening to a podcast.


Castro is a fantastic podcast app that meets all of my expectations. The design and user experience are stellar, and make Castro a standout choice in a crowded category.