This demo app uses manifest v2, which is being deprecated by Chrome in 2022 and will no longer be accepted into the Chrome store. The app, called Daily Collab, is a Chrome extension that lets users embed and transcribe Daily video calls in any Notion page. It includes a prejoin UI feature that allows participants to preview their video before joining a call, select their preferred devices (camera and microphone), and set their username. The prejoin UI is built using custom video APIs and can be customized further. To use the app, users need to clone it locally, install dependencies, and run `npm start`. The app determines its main content based on the value of `callState`, which can be in one of five states: idle, setup, haircheck, joined, or error. When a participant joins a call, they are taken to the prejoin UI, where they can set their username and select devices. Once they have completed these settings, they can click the "Join call" button to join the call. The app uses Daily's methods `preAuth`, `startCamera`, and `join` to manage the call state and device access.