I consider this a decent 3 star book, however I had to take off another star due to a massive flaw. If a book about teleportation screws up the process of teleportation, it is a problem.
Without giving any spoilers, here is my issue with the teleportation in the book:
At 3:14 PM and 3:14 AM, John teleports to and from various places. These locations get further and further away from home each time. Unfortunately, when it is 3:14 PM in the United States, it is also 3:14PM wherever he teleports to. In one case, it was Egypt, which is likely a ~7 hour difference from where John started out. It makes sense that he would be in Egypt at 10:14PM after the teleportation. It would be dark and cold. Had the author not mentioned anything about the time of day, it would have worked fine. However, the author decided to focus on the time, stating something like, "The sun sets around 5pm in this part of Africa. It's going to get cold soon."
My first instinct was to defend the author, thinking that maybe there was a time travel element involved. However, he had a direct communication link with friends back home, which would require some sort of explanation as to how they could communicate in real time with somebody 7 hours in the past.
The author didn't put any effort into the teleportation aspect, which is the whole point of the book (or - shudder - didn't *know* that the Earth is round and it isn't 3:14 PM and sunny all over the world at the same time).
The book itself is written in a typical young adult way (one character is named Ronica (like Veronica, without the "Ve") and she loves to wear fuzzy animal ears), with a love scene thrown in near the end just for kicks. Why YA authors do this, I have no idea. This one involved two senior citizens, too. Thanks for that. I'm sure the YA readers out there were clamouring for it.
I read through the book quickly enough and enjoyed it as much as I could, despite the sloppy misunderstanding of how time works. I can't force myself to read the next two books in the series, though, as they will likely suffer from flat-Earth syndrome, as well.
Request to indie writers: pay something - ANYTHING - to an actual editor. This is more important than paying somebody to draw a pretty cover.