I understand that you are looking for a plugin that blurs out the time bar/indicator on any YouTube video with some form of fighting tag. Not street fights but professional martial arts of all kinds. The purpose is so that the end of the fight isn't spoiled for people who haven't seen it/don't know how long it is.
I have experience in making websites and mobile apps, and I can help you create the perfect browser plugin for your needs. My skills include frontend and backend web development with ReactJS, NodeJS, Vue.js, AngularJS, TypeScript, HTML5 & CSS3, Sass/SCSS preprocessor languages, PHP, Python, Laravel and more. Additionally I have worked with RESTful APIs and have experience working with Heroku as well as AWS cloud services.
I feel confident that my expertise in web development will be an asset to you in completing this project. Please feel free to contact me if you would like to discuss further or answer any additional questions you may have about the project!