What’s the #1 thing you can do to get your apps ready for the 4.7-inch and 5.5-inch iPhone 6’s that are being announced on September 9th? Well, last week I blogged about throwing off the shackles of iOS 6. Assuming you’ve already done that, what’s next on your team’s list of to-do’s?

That’s easy:

Auto Layout.

That’s right: convert all your NIBs/XIBs and Storyboards to use Auto Layout.

Auto Layout has been around since iOS 6, and it gets better with each release of iOS. The old “struts and springs” way of handling view size changes worked fine (mostly) for a simple iPhone or iPad orientation change, but it simply won’t be up to the task for the new, larger iPhones.

The move from the iPhones up through the iPhone 4S (all with 3.5-inch screens) to the iPhone 5 and later models (with 4-inch screens) was easy enough, but the new iPhone 6’s are rumored to come in much larger sizes: 4.7″ and 5.5″. Presumably they’ll retain the 16:9 layout of the iPhone 5, but no good rumors have pegged what their actual screen resolution will be.

(BTW, I’m not completely convinced the simplicity of iOS 7 is all about skeuomorphism: I think Apple and Jony Ive were thinking ahead to larger phones. When the UI is as simplistic as it is in iOS 7–with no background or button graphics anywhere–then a new larger phone is simply about repositioning controls; you don’t have to worry about larger or scalable bitmaps or vector images for buttons and backgrounds.)

Whether you change your apps’ UI or not, it is incumbent upon your team to convert any remaining NIBs/XIBs and/or storyboards to use Auto Layout. Do this now, even if you don’t have time to release a new version of your app before iOS 8 appears (in about a month).

Then, when the new phones are announced (and Xcode 6 and iOS 8 are out of beta), you’ll be able to do the final testing and tweaking of your new Auto Layout-based views for the iPhone 6 models.

Do it now.