Unpack is an iPhone podcast player built around one problem: you hear a term you do not know, and your only options are to stop the episode and search for it, guess, or lose the thread.
Ask instead. Say "Hey Siri, define that in Unpack" with the screen off, shake your head with AirPods on, or tap the word in the live transcript. Unpack reads roughly thirty seconds of transcript around the moment you asked and answers from that context, so "UGC" in a marketing episode is user generated content rather than a country code. The episode keeps playing, then rewinds a few seconds so you catch the run-up again.
Most AI podcast apps summarise an episode, save highlights, or generate chapters. All three work on the episode as an object and assume you understood it. Unpack works on the moment you did not, while it is still playing.
Definitions are generated by Apple's on-device model first, so most lookups never leave the phone and they work with no signal. Only when the on-device model cannot answer does a short transcript excerpt go to a server, with no identity attached, and Settings has a switch that turns that off entirely.
Every term you look up joins a personal glossary sorted by subject, and comes back days later as a short spaced-repetition quiz. Premium adds unlimited lookups, unlimited review sessions, the AirPods head gesture, live highlighting of terms it expects to be unfamiliar, and comprehension quizzes during playback.
Underneath it is a full podcast player: RSS subscriptions, OPML import, speed control, skip, downloads for offline, sleep timer, background audio and a Live Activity.
It does not do episode summaries, AI chapters, episode chat or note export, and there is no Android, iPad, Mac or Apple Watch version.