Preheat grill to medium-high heat and arrange salmon on a large sheet of aluminum foil. (If using individual fillets, you can use individual pieces of foil as well) Fold the edges of the salmon up a little bit around the salmon (this helps to keep the juices around the salmon instead of spilling into the grill).
Season salmon with salt and pepper to taste on both sides. Sprinkle garlic powder and chipotle chili pepper over the top, then drizzle olive oil over the top. Use your fingers to rub oil into the top of the salmon.
Grill salmon for top-down for 5-7 minutes, then flip and grill for another 8-12 minutes until salmon is cooked through and edges begin to brown.
While salmon is cooking prepare the salsa by stirring together all salsa ingredients in a medium bowl.
In a small bowl whisk together butter, honey, and lime juice. Drizzle over grilled salmon. Top with mango avocado salsa and serve immediately.