Cat Person was written and drawn by Seo Kim. She is a storyboard artist for the cartoon Adventure Time, and as far as I can tell this book is her only published work in comics to date.
All of the reviews I have read about this book have been positive. Publishers Weekly called it "a winner. Even the cat jokes are not tired—a difficult feat in a world saturated with feline cartoon books and webcomics." Amy Ratcliffe wrote that it "has its own charming flavor. And, since it is in the style of a journal, you can drop in and out of the book as you please." Whit Taylor called it "a delightful, entertaining read about the little moments in life. Kim’s adeptness at picking up situational nuances, tied with her simple yet whimsical line, hints at an artist who is able to use the inherent ridiculousness of everyday life to her advantage."
Cat Person was published by Koyama Press, and they have a preview and more info about it here. The book has some occasional profanity, so it is recommended for folks who are OK with that.