Tamara Ireland Stone

"After spending the summer at coding camp, Allie Navarro is excited to share the app she built with her friends, until it starts to cause problems between them"--

Calling Anna and Bennett's romance long distance is an understatement: she's from 1995 Chicago and he's a time traveler from 2012 San Francisco. The two of them never should have met, but they did. They fell in love, even though they knew they shouldn't. And they found a way to stay together, against all odds.
It's not a perfect arrangement, though, with Bennett unable to stay in the past for more than brief visits, skipping out on big chunks...