- Does it work with Apple Podcasts, Spotify and Overcast?
-
Any of them, and a browser tab too. It captures the audio an app produces rather than integrating with a service, so the player you use makes no difference to it.
- Does it work on episodes that have no transcript?
-
That is most of what it is for. Apple generates transcripts for eligible episodes inside Apple Podcasts, and Spotify has them for some shows, but an indie feed, an old back catalogue episode or a talk someone linked to has nothing. This does not need the show to have prepared anything.
- Can I keep the transcript afterwards?
-
No. Nothing is written to disk here, ever. If searching an episode after the fact is what you want, Apple Podcasts' transcript is free, and better at that job than this would be.
- Which languages does it caption?
-
Nine, with the language detected for you rather than declared. Worth knowing that Apple's own transcripts cover twelve languages inside Apple Podcasts, so on a supported show in a supported language their coverage is wider. This works everywhere else.
- Does it work on audiobooks, YouTube interviews and recorded talks?
-
Yes. It never knew it was captioning a podcast in the first place. Anything your Mac plays gets the same treatment.