Well, I don't know if you count this as a real-world app yet,
but Perl 6 will support superpositions (known there as "junctions") out of the box. So you'll probably see lots of real programs eventually that say things like:
if $x == 1 | 2 | 4 | 8 {...}
without realizing that they've just generated and used an
any(). (And
TheDamian's forthcoming Perl6::Junctions module is just a reworking of Quantum::Superpositions without all the hifalutin' physics jargon, and with the lofalutin' infix junctional operators.)
And before you ask, yes, we renamed the Perl 5 bitops to something else just so that we could steal them for junctions. That's how important we think they are.