Learn vocabulary from the podcasts you already listen to

Updated September 2026. iPhone, iOS 26 or later.

You listen for hours a week. You meet dozens of terms you half understand. Almost none of them stay, because nothing captures them and nothing brings them back.

Unpack is a podcast player that closes that loop. Look a word up while listening and it is saved, sorted by subject, and returned to you a few days later as a question.

The loop, in four steps

  1. You hear a term you do not know. Ask Siri, shake your head with AirPods on, or tap it in the transcript.
  2. You get the meaning that fits. The definition is built from the transcript around that moment, so it matches the episode and not a dictionary's first entry.
  3. It is saved automatically. Term, definition, episode and subject go into a personal glossary. There is nothing to write down.
  4. It comes back. Days later the app asks you what it meant, as a short multiple choice question. Answer well and it waits longer before asking again.

You never make a flashcard. Listening makes them. That is the difference between a vocabulary app you abandon in week two and one that keeps working because it rides on something you already do.

Spaced repetition, without the homework

Reviews are scheduled by a spaced repetition algorithm, the same family used by long-standing flashcard tools. Each term carries a mastery level from zero to five. Terms you get right move further away. Terms you miss come back sooner. Sessions are short by design; this is meant to fit in the gap before the next episode, not become a study block.

It also checks that you followed the episode

Vocabulary is one half. The other is whether the argument landed. While you listen, Unpack can ask a short comprehension question about what was just discussed. It appears as a small pill you can ignore, and opens into a two-tap multiple choice card if you want it.

Terms marked before you ask

The longer you use it, the more it knows about which words you already have. It uses that to mark, in the live transcript, the terms in the next stretch of audio that it expects to be new to you. Tap one to see the meaning; mark it as known and it never offers it again.

This is the part that needs history. It is more useful in month two than on day one, and that is by design.

What you get to see

A monthly view of how many terms you learned, which subjects they came from, which subject you are strongest in and which you are weakest in, and a streak. Individual terms can be shared as a card if you want to.

Honest limits

Questions people ask

Do I have to use a new podcast app to get this?

Yes, but you keep your shows. Export an OPML file from Overcast, Pocket Casts, Castro or Apple Podcasts and import all of your subscriptions at once on the first run.

What if the show publishes no transcript?

Unpack transcribes the audio on the phone, ahead of your playback position, so terms are ready before you reach them. This is why the app needs iOS 26 or later.

Does my listening history leave the phone?

Definitions come from Apple's on-device model first, and in that path nothing leaves the device. Only when the on-device model cannot answer does a short transcript excerpt go to a Claude proxy, and Settings has a switch that turns that off permanently. Your glossary stays on the device.

How many terms will I actually collect?

That depends on what you listen to. Someone listening to shows outside their field collects several a week; someone listening inside their field collects fewer, and the ones they do collect are the ones worth keeping.

Download on the App Store

Free to download. Ten lookups a day at no cost.

Overcast, Pocket Casts, Castro, Anki, Notion and Readwise are trademarks of their respective owners. AirPods and Siri are trademarks of Apple Inc. Unpack is an independent app and is not affiliated with any of them.