Just as the final school bells were ringing summer last year, Southern California blogger Jessica Kraus (@houseinhabit) was working up a game plan to keep her four boys, ages 2-10, occupied for the long haul. After combing through Pinterest for inspiration, Jessica turned to her husband Mike Krause, a foreman for the pipefitters union, to transform her informal sketches into a modern backyard fort that the boys would favor over couch time.