Cool idea!

i saw earlier today an app that is almost vaguely close, maybe could serve as the frame work! haha https://flathub.org/apps/re.sonny.Playhouse

app has not been vetted by me in anyway, not even downloaded or tried out, so i'm not recommending anything other than the screenshots o nthe link i posted. but lemme know if you try it hah

There isn't an app. But it sounds like you want to bookmark them? You can have bookmark folders just using your browser.