Combine the salmon and lime juice in a large bowl, making sure the salmon is fully submerged (add more lime juice if necessary to cover). Cover with plastic wrap and refrigerate 6 to 8 hours.
Combine the cilantro, vinegar, sugar and 2 teaspoons salt in another large bowl. Drain the salmon, reserving 1/4 cup of the lime juice. Add the salmon and reserved lime juice to the cilantro mixture and toss; season with pepper. Cover and refrigerate, at least 1 hour or overnight.
Just before serving, peel and dice the mango and avocado and dice the apple; fold into the ceviche. Drizzle with the sesame oil and sprinkle with the sesame seeds. Serve with tortilla chips.