Fermat's Last Theorem: implications (there is no new proof)

Solution 1:

Actually, FLT has very few consequences even in Number Theory. Its importance has always been in the methods that were developed in the effort to settle it, and what else could be done with those methods.

Solution 2:

I've read a number theory paper (on Heron Triangles) that used FLT. See Proposition 14 of this paper.