I would trade in the three menu declarations for one with an extra hash level keyed by app name (or actually by lc $app):

my %Menu = {
  app1 => {
         label => "  A",
         MenuItems => [ @MenuItems ]
       },
  app2 => {
         label => "  B",
         MenuItems => [ @MenuItems ]
       },
  app3 => {
         label => "  C",
         MenuItems => [ @MenuItems ]
  },
};
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Then replace other mentions of aMenu, etc. with Menu{lc_app}. For example:

foreach my $app (@sorted_applications) {
      $app = lc $app;
      push @{ $Menu{$app}{MenuItems} }, $app;
}
[download]

Phil