Mia was taken aback. She had expected Emma to be impressed, not unimpressed. She tried again, this time using another comeback from the app: "I'm not arguing, I'm just explaining why I'm right."

As the battle of wits continued, Mia began to realize that the app wasn't the magic solution she had thought it would be. In fact, it was rather...lame. The comebacks started to sound forced and cheesy. Emma, on the other hand, was effortlessly cool and funny.

"What's that?" Emma asked.

Mia grinned mischievously. "That being bratty and witty is not about using cheesy comebacks, but about being yourself and having fun with the people you love."

As soon as the summer break started, 16-year-old Mia's excitement turned into boredom. She had already binge-watched all her favorite shows, played every video game she owned, and even organized her closet (twice). Her parents, trying to encourage her to be more productive, suggested she download an app to learn a new skill or hobby.

However, Mia wasn't interested in anything "productive." She wanted something fun, something that would make her sister, Emma, jealous. Emma was 14 and always seemed to be one step ahead of Mia, whether it was with the latest fashion trends or the coolest gadgets.

Mia's eyes landed on an app called "Bratty Sis." It promised to provide her with the most epic, savage, and snarky comebacks to deal with her annoying sister. The app claimed to have a vast library of witty one-liners, clever insults, and humorous put-downs that would make Emma green with envy.