In a large glass bowl, mix the cider vinegar, mustard, garlic, lime juice, lemon juice, maple/agave syrup, salt, and pepper. Whisk in the coconut oil. Place chicken in the mixture. Cover, and marinate 8 hours, or overnight.
Preheat an outdoor grill for high heat.
Lightly oil the grill grate. Place chicken on the prepared grill, and cook 6 to 8 minutes per side, until juices run clear. Discard marinade.
Serve with some fresh leaf salad or summer vegetables.