Put the apple, sugar, garlic, fresno pepper, soy sauce, sesame oil, apple cider vinegar, and miso paste in a small food processor and process until smooth.
Place shrimp in a large bowl, pour the marinade over, and let marinate at room temperature for 20 minutes.
Preheat a grill to high.
Remove shrimp from the marinade. Thread shrimp onto skewers and grill for 2 - 3 minutes per side.
Serve immediately with mustard soy dipping sauce.
To make the mustard dipping sauce, place soy, vinegar, and mustard in a small bowl, whisk to combine.