操作步骤：
1.安装扩展
2.打开目标视频网站
3.点击扩展，点击相应播放倍数，目标网站视频按选中播放倍数播放

Google Reverse Image Search is a simple tool that lets you search the images reversely on Google Images and find the other copies of the very image you are looking for on the web.

Brings annotation support back to YouTube™!

ICPBravo Access ICPBrasil and General PKI Extension.

Remove unwanted contents on the Facebook website, including sponsored posts and recommended pages/groups. Supports both desktop and mobile Firefox.

Easily connect with friends and family while you browse internet. This add-on brings conversations to life with photos, emoji, and even group video calls!

Write your email in Markdown, then make it pretty.

Use right-click menu to download YouTube Videos without any appearance changes on your webpages. Works on YouTube video links on any pages.

Generate QR Code from the url of current page, link or selected text. And decode QR Code in image.

Enable dark mode in inbrowser messenger.

Youtube Ad Skipper is an extension that auto skips ads after youtube provides a skip ad button. It does not block an ad.

Watch Netflix, HBO Max, Prime Video, Disney Plus, Hotstar, Hulu, Paramount Plus and Peacock TV Together In A Sync

Block Ads Seamlessly on Facebook.com

Cross-browser userscript for maximum lurking on 4chan.

Watch YouTube in the full-HD quality or the highest available one

Unlocks medium.com for unlimited reads, no membership required

Use the context menu (right click) to search on YouTube any text from other websites.

Allows to visualize the electricity consumption and greenhouse gases (GHG) emissions that your Internet browsing leads to.

Enable use of the Cisco Jabber Guest add-on for public-to-business voice and video calls.

Access to WhatsApp Web from within a toolbar panel and get badge notification of unread threads

Free online YouTube video downloader, download online video from YouTube for free just with one click, fastly and easily!

Copy ShortURL lets you instantly create a short URL for web pages that you visit, so you can easily share links with friends.

Blocks the ”seen” feature of the facebook messenger, and your friends will no longer be able to see if you read their messages.

Eight Dollars can help you tell the difference between actual verified accounts and twitter blue users.

Translate web pages, highlighted text, Netflix subtitles, private messages, speak text, and save important translations to your personal dictionary to learn words in 130 languages.

Share to Facebook, Twitter, WhatsApp, email, and any other sharing or saving service quickly and easily with one share button.

Fill out web forms automatically with a single click

Get around Twitter's login modal and still scroll tweets. This extension will add a button to your toolbar. When Twitter throws up a login wall, press the button and you'll be able to continue browsing.

1. Install Extension
2. Play video in your browser
3. Click the KV icon then click respective links to download
The most popular Keepvid.site website's All Video Downloader Extension

Adds a button to the address bar to get the current url as a qr code