There is no single "hack page," but rather several established repositories where you can browse and download userscripts: Tampermonkey: Home
Tampermonkey is a leading userscript manager used by over 10 million people to customize and "hack" their browsing experience by injecting JavaScript into web pages. While often used for productivity—such as adding a social media share button or automatically filling forms—it is also a popular tool for installing game "hacks" or UI modifications.