Penguin Random House.

Lucy is super excited about coding club at school. She has an idea for an app, and can't wait to get started. Her excitement turns to disappointment when she's put into a work group with girls she barely knows. All she wanted to do was make an app that she believes will help someone very special to her. When she begins to get cryptic coding messages and needs help translating them, Lucy discovers that coding and friendship take time, dedication, and...