SOLVED. YA Thriller. Group of high school students download app and do tasks to get rewards. Spoilers ahead. [s]

[Ginny]

I read a book a while back about this group of high schoolers (there are multiple narrators)
and it starts with these kids at school getting all this new tech. The others figure out it's
based on an app they can download, and are asked to complete seemingly mundane tasks for
big rewards. The tasks start to get more dramatic, however. One girl is told to switch pills
from one bottle to another in a characters house. Another tells a girl to switch chocolate chip
cookies for peanut cookies. This leads to a girl's death. The story finally culminates in a shed
where a character was tasked to burn down a shed with someone inside. I would really like to
read this book again, please help!<3

[Becca]

Need by Joelle Charbonneau?

[Ginny]

oh my gosh that’s it!! thank you so much:)))