It first appears in "Butterfly Effect", where Lisa got a job there, after Leni (who had become a genius after receiving several blows to the head) made a fool out of Lisa after saying one of her equations was done in an incorrect order, making her lose confidence of her studies. However, all of this did not happen, because it was all part of Lincoln's fantasy.
It appears again in "Come Sale Away", where the Loud kids, after seemingly selling Lily's blanket, arrives and asked Flip to buy the "blanket" from him. It turned out to be a scam by Flip, as he has conned all the Loud kids for their garage sale money, and the "blanket" he gave them was actually a washcloth. At the end of the episode, the roof of the building exploded after Flip intended to use Lisa's chemicals as laundry detergent.
It is the main location in "Intern for the Worse", where Lincoln and Clyde apply for an internship there. Flip hires them and shows them all the ways of running the store, while also demonstrating how he cuts corners to save money. He then informs them of a managerial promotion where the one with the position will get a special cup that gives them unlimited Flippees. This puts a grudge between Clincoln McCloud as their love of Flippees gets the better of them and they keep doing better than the other to get the cup until they find out that Flip was using them all this time to do menial and backbreaking tasks for them. Seeing how they were tricked, the two interns reconcile and decide to look over the surveillance tapes and inform Flip that they will post the footage online. Flip, not wanting his store to get shut down, pleads them to stop and insists on doing what they ask for if they promise not to upload the footage. They oblige and boss him around, making him do all kinds of tasks that puts him through what he put them through and cleans up his store, all while enjoying as many Flippees as they please.
In "Any Given Sundae", the Loud family create a special sundae just for Lily after the one she had at Aunt Pam's Parlor got destroyed.