No one site does it all or lists it all.
Just because you can't find an app at one site, doesn't mean it's not out there.
There are many excellent software searching sites for OS X users.
Each one does things in a slightly different way,
each having a different design goal and functionality.
Remember that OS X can also run just about any program written in the more
universal languages, such as Java, Perl, Python, Ruby, Tcl, etc.
There are so many programs that OS X can run, in fact, that no site dare
try to list them all.
Most only list programs custom written for OS X.
I encourage you to check out these sites to see if they can help you out: