You're referring to the popular fan-made project "All the Fallen Booru"!
"All the Fallen Booru" appears to be a collaboration project where multiple people contribute to developing a unified feature-rich platform. All The Fallen Booru
Would you like more information on this project or help with contributing? You're referring to the popular fan-made project "All
For those who might not know, Booru is a popular open-source image booru (board) software used for creating image galleries, often used by fans of anime, manga, and other visual media. often used by fans of anime
Here's what I could gather about putting together the feature: