Got this as part of the Story Bundle.
This is a sequel to John Gone. While I found that first book disconcertingly nihilistic, this one is disconcertingly amusing. Strange things happen for no reason, and it takes place in some sort of parallel dimension where teenagers can go to Vladivostok by train without passports.
Also, the rules that control the teleportation device seem to change every once in a while, and some things are just never explained. Finally, the author seems to have no idea whatsoever about how computer networks work (the thing with the signals is basically Star Trek: Voyager level technobabble, except it's about technology that's 50 years old already).
In any case, liked it better than John Gone, I would give it maybe 2.5 stars.
While I am not really a big fan of these books, I decided to buy the 3rd, "Company Men" because I want to see what happens next.