Here's how you can get the YouTweak extension for Chrome. YouTweak enhances the YouTube experience.
1. Go to the YouTweak page in the Chrome web store.
2. Click the Add to Chrome button.
Here's a description of YouTweak:
"Features: Remove Subscription Videos - This feature makes it easier to delete unwanted videos from your YouTube homepage. The current YouTube layout seems to discourage the use of the 'Hide video' option previous layouts featured prominently. This feature intends to fix this, giving the user a per-video dedicated button for the removal of the video. This button instigates YouTube's own hide video feature which means that hiding it with this app also hides it if you were to sign in from a different computer without the app.
Remove Watched Videos - This feature makes your homepage much cleaner by removing any subscription videos that you have already watched. When activated you will notice a new button added to the left navigation column of the homepage. When clicked any videos in your current subscriptions are removed.
Subscription links are made HD - This changes all video links from your homepage to link to HD versions of these videos. (This feature is currently only compatible on quality up to 720p).
Youtube Subscriptions as Default Page - Automatically redirects you to Uploads only of your subscriptions. This changes the URL that the icon at the top left of every YouTube page links to. The default link is to "youtube.com" which shows all of your subscriptions and recommended videos mixed together. By default the app redirects to "youtube.com/feed/subscriptions" which only shows your subscriptions videos (but this can be set manually to any URL).
Stop autoplay of videos - This disables YouTubes auto play feature when opening a new YouTube video but still allows the video to be buffered. This means that the video will still load and be ready for you when you click play.
Remove all subscription videos - This adds a button to the homepage which when clicked will cycle through all of your subscriptions and remove them, leaving you with a clean homepage ready for new subscriptions to be easily visible. (Example for use could be after returning from holiday and clearing the weeks of subscription buildup, or when a channel uploads many videos that clog-up your subscription feed)
Load all subscription videos - This adds a button to the homepage which when clicked loads all of the pages of your subscriptions into view, allowing you to browse them all without having to reload the page. This can make it easier when removing videos you do not want to watch."
For more, see the original article at the link below.