iOS 7 is Apple's most drastic operating system redesign yet, so it's only fitting apps would want to key into the new aesthetic too.

Facebook, Twitter, Evernote and others all took cues from the flattened look of Apple's new OS, releasing updates for in the App Store left and right today.

On the whole, the made-over applications should fit right in with iOS 7's non-skeuomorphic principles, though there are still shades of texture and depth. Most, however, fall in step with 7's style.

We'll start with the big fish: Facebook released version 6.5 of its app, complete with "an all-new look and feel for iOS 7." You're too kind, responded iOS 7.

New Facebook functions

While iOS 7 elements have slipped into Facebook's app (the skimmed down top section screams "7"), Facebook took it one step further and created an entirely new way to navigate on the iPhone.

Most notably it placed the navigation bar along the bottom of the screen. Tapping here will pull up the News Feed, Requests, Messages, Notifications and More. "More" queues Timeline, groups, events and other info.

Facebook

What's really dynamic, as reported by Engadget, is that as you pick between the five main tab options, the screen will automatically switch to whatever you're looking at.

The different pages will automatically save on each screen, so you can read a new message then pick up where you left off in your News Feed without having to scroll back through previously-viewed content.

The More option will also remember where you've been, turning it into a more customizable creature than simply giving you "more" of the options you don't really want.

The navigation changes are only coming to the iPhone, and while iPhones running iOS 6 and iOS 5 will support the updated app, some design elements will differ.

Twitter and a whole lot more

Twitter meanwhile also retooled its app for iOS 7, though the application is compatible with iOS 6 and iOS 5 just like Facebook. The core functions are largely the same, but Twitter has cut down the top tool bar, sticking with a basic blue and white scheme and line-drawn looking icons.

Twitter app
Simple is so hot right now

Evernote took, well, note of the "clean, simplicity of iOS 7" in version 7.0 of its app, plus added some navigation functions like jumping from your most recent note back to the home screen. There's also a new audio recorder that should make it easier to listen and type at the same time.

The whole app has been stripped down, making accessing main Evernote functions markedly quicker.

eBay, Kindle, Foursquare, Pocket, Yahoo Weather, Pandora (as iTunes Radio releases...interesting) and plenty more took advantage of iOS 7's release to tinker with their iOS apps, all of which you can check out in the App Store right now.