Time Between Us, by Tamara Ireland Stone

In 1995, Anna meets Bennett, a boy from seventeen years in the future, who has traveled back in search of his sister (he lost her on a previous trip through time).  However, he falls for Anna and stays because of her.  But there are issues with remaining and, while no one understands the dangers of his presence in the past, he fears that it could cause great harm.

Time travel stories are not that common in YA and the combination of teen romance with such a fantasy premise is appealing.  It helps that both Anna and Bennett are likeable and that they make a good couple.  Also, that it's intelligent writing (time travel books have to be to grasp at all the paradoxes and Stone does a good job of laying out the logic and the principles of time travel without slowing things down during most of the book).  Some of that pacing is lost towards the end, but it mostly comes together.  What does get lost are some of the subplots (like Anna's running or her relationship with her friend Justin), but overall the novel worked for me and I found it entertaining.