The popular iPad magazine Zite added Instapaper integration Wednesday.

If you build it, they will come. And in droves.

In the world of top-notch iPad apps, that certainly seems to be the case, and this week the new iPad magazine Zite has been one of the hottest things around.

In this space, evolutionary change comes fast. And to many, Zite is already being seen as the next step past what applications like Flipboard have been able to do. Flipboard became Apple's top iPad app of 2010 because it gives users a lovely presentation of personalized news based on their Twitter and Facebook accounts, as well as other custom-selected feeds.

Zite (see video below), however, appears to have stolen Flipboard's thunder. The app is exploiting Flipboard's lack of dynamic learning and giving users constantly updated feeds based on what they've demonstrated they're interested in. The app keeps track of the kinds of stories users choose to read and incorporates that intelligence into its algorithm for what it serves up. As well, it aims to give you less of what you're not interested in.

Zite: Personalized Magazine for iPad from zite.com on Vimeo.

In the first five days since being released, Zite--produced by a small team in Vancouver, B.C., led by CEO Ali Davar--jumped to the No. 1 spot for free apps in Apple's App Store, and has already been downloaded 120,000 times.

And now, the company says it has responded to its users' top request--adding Instapaper integration. As of 11:30 a.m. PT today, users will be able to access the feature, allowing them to automatically and easily save articles for later without having to leave the Zite app. "The integration with Zite will place an Instapaper button on Zite recommended articles," Davar told CNET, "enabling Zite users to more easily save these articles to Instapaper. The integration uses Instapaper's API."

Zite is moving quickly with new additions to its app, and seems intent on listening to its fast-growing community of users. With more than 4,000 followers of its Twitter feed, it's tuned in to what the community wants.

The question now, of course, is what will Flipboard and those who produce other iPad magazine apps do to respond.