Jumper: Griffin's Story, by Steven Gould
This is the third in the Jumper series by Steven Gould, it's the backstory of one of the characters in the movie.
This one didn't make me quite as upset as Reflex did, but it had its moments! I just felt so incredibly bad for the kid. He's so little and he's having to deal with stuff that no one ever should. The bad guys are so ruthless in pursuing their goals and it makes my heart break every time someone close to him gets hurt.
I still haven't seen the movie, but I did read a couple reviews that complained that certain things weren't really explained. I think some of that does get explained in the book, at least to an extent. But not having seen the movie I obviously can't be sure.
I do hope that there'll be more books though! I really like these even if they do have parts that make me cry. But I figure an author that can make me care about a character enough to get emotional when stuff happens to them is a very talented person!