Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
The Mac App Store is for Macs (as its name indicates), not IOS devices:
http://www.apple.com/osx/apps/app-store.html

See also:
http://www.apple.com/support/mac/app-store/getstarted/

well, Trillian website directed me to this page on apple.com when I clicked on "download" link here...
https://www.trillian.im/download/
(I guess they can't detect whether you're on a desktop or phone....;-)

either way, in case you misunderstood: I'm on a regular desktop..

----------

Are you on your Mac with the Mac App Store installed?

I have never had to install a "store" to download a free app...

I'm on a desktop, not on a phone...

thank you..
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.