This review is spoiler free!!
My rating: 3/5 stars
This was okay. Just okay. It was just so similar to Pivot Point, which was way more awesome. With Pivot Point, there was a purpose to the two different alternate universes; here there wasn't. Which just made the whole book feel pointless. I probably would have liked this if I hadn't read Pivot Point before. Honestly, if the concept intrigues you, just read Pivot Point.
I also had a difficult time keeping track of each timeline. They're labeled with different names, but it was still hard to remember what had happened to each one. There's really not much more to say - everything about this book was just a big meh for me.