If your goal is to download YouTube videos for offline viewing, you should avoid random websites promising a "ytboob install" and instead use established, reputable tools.
There is no desktop "app" that needs installing (unless you use Windows 11 with Android subsystems). Instead: ytboob video install
The keyword is a red flag – but the genuine need behind it is understandable: people want to save YouTube videos locally. If your goal is to download YouTube videos
Fake video installers often claim: "You need the YTBoob Codec Pack to watch this video." This is a classic trick. The "codec" is actually ransomware or adware. ytboob video install