CurseForge Download Replacer is a free Chrome add-on developed by Matt Worzala. As the name suggests, this add-on replaces the download links from CurseForge, a popular platform for downloading mods and modpacks.

One of the main features of this add-on is that it changes the "Install" URL from loading the Twitch client to simply downloading the zip archive of the modpack. This can be useful for users who prefer to manually install modpacks or who don't want to use the Twitch client for various reasons.

Additionally, CurseForge Download Replacer attempts to remove ads from modpack pages. It does this by removing `iframe` elements from the DOM. However, it's important to note that if CurseForge starts using `iframe`s for anything besides ads, this could potentially cause an issue.

Overall, CurseForge Download Replacer is a handy add-on for Chrome users who want a more streamlined and ad-free experience when downloading mods and modpacks from CurseForge.