Update README.md

README.md

@@ -2,7 +2,7 @@
   <img src="img/icon24.png"/> FreshView for YouTube™
 </h1>
 
-[FreshView for YouTube™](https://chrome.google.com/webstore/detail/freshview-for-youtube/eckknmnfoohbeklmjlidmfdlakndcfkm) is a Chrome extension that hides YouTube™ videos which users have already watched.
+FreshView for YouTube™ is a [Chrome](https://chrome.google.com/webstore/detail/freshview-for-youtube/eckknmnfoohbeklmjlidmfdlakndcfkm) and [Firefox](https://addons.mozilla.org/en-US/firefox/addon/freshview-for-youtube/) extension that hides YouTube™ videos which users have already watched.
 
 ---
 
@@ -23,8 +23,8 @@ The [js](js) directory contains the following scripts:
 | **File**                          | **Purpose**                                            |
 | :---                              | :---                                                   |
 | [album.js](js/album.js)           | Implements a container for Videos.                     |
-| [background.js](js/background.js) | Activates the extension in the Chrome toolbar.         |
-| [injection.js](js/injection.js)   | Attaches listeners to Chrome storage events.           |
+| [background.js](js/background.js) | Activates the extension in the browser toolbar.         |
+| [injection.js](js/injection.js)   | Attaches listeners to browser storage events.           |
 | [logger.js](js/logger.js)         | Wraps `console` to control the visibility of messages. |
 | [manager.js](js/manager.js)       | Finds and manages Videos on a page.                    |
 | [popup.js](js/popup.js)           | Attaches listeners to the extension UI.                |
@@ -39,13 +39,13 @@ When the DOM is mutated, FreshView polls the DOM for HTML elements that match th
 1. The view progress of a Video is derived from the red bar shown along the bottom of a YouTube™ video element.
 1. Only DOM `childList` mutations trigger a poll request.
 1. DOM mutations that occur within 200 milliseconds of one another are batched into a single poll request.
-1. The view threshold slider is only synced on `mouseup` events to avoid exceeding the `chrome.storage.sync` quota.
+1. The view threshold slider is only synced on `mouseup` events to avoid exceeding the `storage.sync` quota.
 1. YouTube™ videos that appear in the Autoplay panel or the History tab are ignored.
 
 ### Screenshots
 
-#### FreshView for YouTube™ UI
-![FreshView for YouTube™ UI](assets/popup.png "FreshView for YouTube™ UI")
+#### User Interface
+![FreshView for YouTube™ UI](assets/popup.png "FreshView for YouTube™ User Interface")
 
-#### Video Progress Demonstration
-![Video Progress Demonstration](assets/progress.png "Video Progress Demonstration")
+#### Watch Progress
+![Video Progress Demonstration](assets/progress.png "Watch Progress")