Having an iOS version is a lot different than being iOS based. I use Dropbox, Instapaper and Pandora on iOS, but I use the web-based version from my laptop just as often.

I think many if not most people, especially in Wired's audience, access these tools from multiple platforms. If you had a list of "essential" desktop apps or web services, would you exclude those which also had an iOS version because they weren't exclusively on your target platform?