The Google Pixel 4's (unimaginatively) titled Recorder app is arguably one of the best on the market as it can do a lot more than just record audio. The application uses its AI secret sauce to perform real-time voice transcription into text, and it can locate music and specific words inside the audio file without an internet connection. For those who missed it, here's a short video of the Recorder app in action.
An unofficial version of the Recorder app is available for all devices
As expected, the Recorder app is a Pixel 4 exclusive and will be for some time. Google is yet to officially comment on the app's availability on older Pixel devices., On a Reddit thread, a commenter asked why they are not currently able to use the Recorder on their Pixel 3 XL. One day later, a verified Reddit handle by the PixelCommunity stated that the app would eventually make its way to older Pixels. Considering the informal nature of the announcement, it is unclear as to when it'll make its way to older Pixel phones. Non-Pixel users will likely get it too and might have to wait a bit longer for the privilege.
A few days after the app made its debut on stage, an unofficial version of it surfaced online. It was a pre-release version of the application and lacked some key features. However, it gets the job done and works flawlessly, for the most part. You can download it using this link. I've been using it on my Galaxy Note 10+ for the past couple of days and it's been working flawlessly. The transcription feature is undoubtedly the crown jewel of the app. It is far from perfect and has a tough time transcribing some words (especially NSFW ones,) but it should get better over time. The only problem is that you're going to have to manually install every subsequent version as there is no way for a non-Play Store app to update itself automatically.