Best nerds forever!
(Book)

Finn McAllister is a completely normal middle schooler: he hangs out with his friends, he plays video games, he rides his bike... And then he dies. Now Finn is a ghost, with all the perks that come along with being able to walk through walls--and people! He can stay up as late as he wants, there's no more school, and he can eat every ice cream flavor without getting sick. Talk about awesome. He's even made a new friend, Isabella Rojas, who's also a ghost. But soon the thrill of playing invisible tricks on people isn't so fun anymore, as Finn realizes that he and Isabella can't move on to the afterlife. Now the two must discover their unfinished business before it's too late and they're stuck as ghosts forever.