I've definitely had a few encounters where it seems there's a good chance the average, non-technical user, considers 'app' to refer explicitly to iOS applications. I remember somebody wanting to work on a project asking if I had written any 'apps', I assumed he meant applications and I listed off some of the more interesting projects on various platforms. He seemed utterly confused that I was talking about things that were not running on an iphone.

It's a biased selection but, Google's Page Rank certainly says that the public tends to "link" the term 'App Store' to 'Apple' in a pretty consistant manner

http://www.google.com/search?sourceid=chrome&ie=UTF-8...

On the other hand, half of the "related searches" on that page are "nokia app store", "android app store", "samsung app store", etc., which are not the official names of any of those brands. Its possible that the public uses more formal names when linking but less formal names when searching.

The "there's an App for that" campaign by Apple has definitely helped cement that as a possibility. I'm pretty sure when folks use / mimic / parody that phrase, they're always referring to Apple's use, not some generic "app".