We all know that iOS 7 is imminent. We're into Beta 3, so we can make semi-accurate guesses on when the full version will get released. So to all of our clients, I'd say you may want to think about having your app updated to iOS 7 VERY SOON.
Who remembers when the iPhone 5 came out? We briefed our clients. We said
"We should probably do some work on your app and make it utilise the 4-inch screen".
Understandably, many of our clients wondered what benefit they'd derive. We were going to charge for the modifications; on first glance it could seem that we were just looking to get more fees out of them. We weren't; we were actually giving them the correct advice.
The conversation kinda went like this:
"So what happens if we don't modify it, will it run on an iPhone ?5" "Oh yeah, it will run. Apple have this special 'letterbox' mode" (where we proceed to explain the letterboxing) "Oh, that sounds fine let's leave it so" "Are you sure? because..." (where we explain letterboxing is kinda horrible) "No, let's just leave it"
So we did.
What happened when the iPhone 5 hit our shores?
Well, within days of having it, a letterboxed app was pretty much an insta-delete.
At that point, our clients came back with urgent requests to make their app 4-inch compatible.
I predict the iOS 7 effect will be worse. Within a week of running full time, those apps which haven't been modernised to look like an iOS 7 app will look very old. They too will become insta-deletes.
If you have an app in the store, We'd highly recommend looking at modernising them pretty quick.
Update: Stewart Curry suggested I also make reference to adoption rates. What we know is Apple users upgrade very quickly. When iOS 5 launched, it caused a massive worldwide spike in internet traffic. iOS 6 was launched just 9 months ago (at time of writing), and is currently on 94% of all iOS devices according to Apple's figures (Unfortunately, this link is dynamic so will change over time. Trust me. When I wrote this, 94% was the figure). So, don't kid yourself it will only affect "power users". Not being iOS 7 ready will affect "all users"