In the alternate timeline of Kingdom Come/The Kingdom, Barry is one of two children of Wally West. He grew up in constant conflict with Wally over whether or not he was going to become 'Kid Flash'. Barry showed no interest in ever being the Kid Flash, suggesting his younger sister Iris be the one to take up the mantel. Even though Iris would have been more than happy to take on the role of Kid Flash (which she eventually does) Wally was determined that his son Barry was the one that should take up the mantel.
When a crisis hits their world that threatens to destroy their entire timeline, Wally once more tries to convince Barry that he's needed as a hero. Barry responds by trying to 'cram a whole lifetime into one day'. He spends most of what might be his last day on Earth trying to get drunk, which he can't do because of his super metabolism, and getting a large turtle tattoo on his chest. Iris tracks him down and tries to appeal to him to help stop the end of the world. Barry explains to her that he has no interest in being the hero, and more over that she is far more suited for the task.
Barry is last scene telling his father Wally that Iris has gone off to save the universe and that she was always the hero of the family having become one with less than no motivation/support from her father. Because of this Wally comes to accept Iris for the hero that she has become, though he hasn't given up on converting barry to the flash way of life just yet.
Barry is last seen congratulating his sister on saving the world, and running off with the rest of his family while still claiming there is no way you'd ever see him in lightning bolts.