Sincerely, Carter by Whitney Gracia Williams is a stand-alone romance about best friends who fall in realization that they have always loved each other. Filled with quirky humor, absolutely hilarious flashbacks to grade school and the communication between the much younger versions of Carter and Arizona, and with a few angsty deep-feels thrown in for good measure, this book was a "devour in one sitting, the hell with the world" type book for me. 
 Carter and Arizona have been best friends since fourth grade (or fifth depending on which one you are talking to) and they have always been platonic, never looked at each other that way, cannot understand why no one ever seems to believe them. Until that moment, of course, when a switch is flipped and they suddenly cannot STOP seeing each other as more. They already know each others dirtiest secrets and dark pasts so there's nothing to hide, right? 
 I loved it. I know you will too. The interactions between ALL the characters just flowed so well. It was a pleasure to read. Except at around 90% in when I wanted to gut punch Ari - Oooh she made me mad!!!!