A Cleaner YouTube is a browser extension for Chrome, Firefox, and Safari. Once installed A Cleaner YouTube allows you to display YouTube videos without any of the "related videos," comments, or display advertising. There are other tools that do the same thing, but what makes A Cleaner YouTube different is that not only can you display videos without the related materials, but you can also search YouTube without viewing any of the "related videos," comments, suggested videos, or advertisements. I have before and after images displayed below.
Applications for Education
If you work in a school that allows you to access YouTube in your classroom, A Cleaner YouTube could be a great tool to add to your browser. With A Cleaner YouTube installed you don't have to worry about accidentally displaying an inappropriate comment, advertisement, or related video.
H/T to Make Use Of.