Place the chicken breasts in the slow cooker.
In a bowl, whisk together BBQ sauce, apple cider vinegar, brown sugar, Worcestershire sauce, smoked paprika, garlic powder, onion powder, salt, and pepper.
Pour the sauce mixture over the chicken. Cover and cook on low for 6-7 hours or high for 3-4 hours, until the chicken is tender and easily shredded.
Use two forks to shred the chicken directly in the slow cooker, mixing it well with the sauce.
Serve the shredded BBQ chicken on buns, over rice, in tacos, or with a side of coleslaw.