けものブック is a Chrome add-on that allows you to customize your Facebook reactions. With this extension, you can change the default "Like" and "React" buttons to fun Japanese phrases like "すごーい！" (Wow!) and "たーのしー！" (Fun!).

This add-on is a great way to add a touch of creativity and excitement to your Facebook experience. Instead of the usual reactions, you can now express your emotions in a more playful and unique way. Whether you're browsing through your friends' posts or reacting to a funny video, けものブック brings a fun twist to your social media interactions.

Additionally, けものブック allows you to switch between the Japanese and English interface of Facebook. This feature provides flexibility for users who prefer to navigate the platform in their preferred language.

Overall, けものブック is a free Chrome extension that adds a fun and customizable element to your Facebook reactions, allowing you to express yourself in a more unique and playful way.