Welcome!
The website hosts automatically created card rotation charts and statistics for the cards from Love Live SIF All Stars, updated daily. These charts can help you figure out which girl is most likely to receive a card next based on statistics like how many cards are remaining in the current rotation and how long it's been since their last card.
Unfortunately this site does not function without Javascript enabled. I know Javascript sucks, yeah.
That said, this site does not and will never have any ads, trackers or other nasty crawlies so you can safely enable scripts if you're feeling brave.