Along with iOS 7, Omni released a slew of new Apps today optimized for iOS 7. My favorite and most used, OmniFocus 2 for iPhone. You can read David Sparks comprehensive review here. I've already purchased my copy and while I love the redesign and find it very functional, I'm really going to enjoy the support for background syncing, ability to quickly defer tasks and easy access to forecast view.
Along with the 2.0 releases, Omni also launched new versions of OmniOutliner and OmniPlan for iPad. In addition to bringing great new design, these apps pack in new functionality and are designed to take full advantage of the new features of iOS 7.
You can read more about the releases on Omni's Blog or check out their redesigned site.