After the WWDC keynote on Monday night we fired off some emails to developers to gauge their reaction to the announcements. 

[Read our other developer reaction stories: OS X Maverick: Apple's developers discuss Apple's new love for power users and Mac Pro 'Astounding', MacBook Air 'Awesome' - WWDC developers react]

Generally feedback was very positive to iOS 7, although a number of developers commented on the similarities between Android, Windows Phone and iOS 7. 

Some developers had been concerned about the direction the expected redesign would take. After months of rumours about Jonathan Ive’s plans to revamp the operating system and remove all traces of Scott Forstall’s skeuomorphism, a number of developers were bracing themselves for change. 

One of them was Binary Formations owner Kevin Hamilton. He told us: "I have to admit that I was really sceptical, but now I'm relieved."

Keith Blount developer of Scrivener at Literature & Latte isn’t yet ready to draw his conclusions. Blount said: "I'm reserving judgement on the new UI for the time being, because radical design overhauls to something you use all the time are bound to take some getting used to, and besides, I've never been good with change."

Another iOS developer described the new iOS as being like Marmite. Andrew Till director at Plastic told us: “iOS 7 is a real love it or hate it design. It's admirable just how much they've changed it, but it's jarring.”

For some, change is good, however. "We're impressed at the degree of change Apple opted to pursue for iOS 7 and we're delighted at the usability improvements," said Greg Scown co-founder of Smile Software

IGG Software founder and president Ian Gillespie expects that users will adjust to the change in design quickly. “The new UI takes some getting used to, but I'm sure that in six months, when I pick up an iOS 6 device, it will feel and look old,” he said. 

The new iOS 7 is like Android, Windows Phone... 

Of course with the new look came numerous comments that the new iOS 7 takes its inspiration from Android and Windows Phone, this was, after all, what all the rumours had suggested. 

Blount said: "My first reaction, admittedly, was that the flatness of the design looks more like something I might expect from Microsoft, so I was somewhat surprised by this direction, despite all the rumours."

However, Blount admitted: "I love the flatness inside Safari and other apps. With this flat, almost on-paper-ish look, they seem to have performed the trick of making the contents of the apps look more analog while at the same time eradicating the skeuomorphism. And I'm very glad to see the back of skeuomorphic design on both iOS and OS X."

Ray East marketing associate at BeLight Software noted that there will be challenges, describing ridding iOS of skeumorphism as a “gamble”. He told us: "It's going to take some getting used to for a large majority of users, although iOS 7 looks fresh and brings a lot of long overdue improvements, such Control Center and AirDrop. It was quite a gamble ridding iOS of skeuomorphism. We'll see how easily the transition period passes.”

Public Space developer Frank Reiff had an interesting insight into why now is the time for Apple to move towards a new look operating system. He explained: "It is true that iOS 7 looks more like Android than iOS 6, but I think that's not a bad thing. The iPhone and the iPad were aimed squarely at bringing people outside of the usual PC crowd onto new mobile touch-based devices and iOS reflected this in many of its design decisions. Android has always assumed a more on tech-savvy audience and its design and core values reflect that."

Reiff added: "Now Apple's mission has shifted from bringing people onto the platform to giving them more capable devices and I think iOS 7 reflects this new focus on capabilities. It is now safe for Apple to assume that most iOS users have owned such a device before and they can assume more familiarity with core concepts, and that profoundly affects all design decisions." 

A number of developers noted that even if it’s similar to Android, because Apple has designed it, we can be sure that iOS 7 will be better. MacAce CEO Gary Hall said: "If anyone can use Helvetica, take away all the gloss and shadows and use primary colours and get away with it, it's Apple - if it were anyone else, we'd all be criticising it much more, but this is Apple - they do design better than anyone else."

In many ways it doesn't matter if Apple's iOS is like Android, Apple will do whatever Google does better because they control the hardware and the software. This theory was put forward by Reiff, who suggested that: "Apple's design team has a better grip on what is possible and what is important than Google with Android. Apple always matched iOS and hardware capabilities very well. If something was too power or CPU hungry to run well on the current generation of devices, Apple simply didn't do it. Google just put it in anyway."

Reiff continued: "The result has been that even very low powered devices like the original iPhone always felt very responsive and fast. Conversely, even very capable Android devices always feel a little bit sluggish."

"We've now reached the point where mobile devices are capable enough to run something akin to a "full OS" and Apple is taking advantage of it," added Reiff. 

Redesigning icons in iOS 7

Icons see to be a bone of contention with our developers. Blount told us: "I'm yet to be convinced by the new icons, as I really liked the gloss of the old ones."

However, it’s not just the new look that has raised concerns, a couple of developers point out that the strict guidelines for icons will make it much more difficult for developers to make their apps distinguishable. 

BeLight’s Viktoria Naumova told us that simplifying app icons to such an extent will limit designers. “Where it used to take a designer days to create a realistic, highly-detailed icon with pseudo textures, the new flat icons can be authored in no time at all. But that raises an issue: Icon quality is often the first step in assessing an app. If an icon is attractive and obviously designed by a pro, you're going to open the app and check it out. But what happens when the icons in the iTunes App Store begin to resemble each other a bit too much? Often the details set professional icons apart from amateurs.”

Karen MacLean of Open Planet Software expects that developers will be redesigning their icons to adapt to Apple’s new guidelines. “One aspect of iOS 7 we have noticed is that the rounding on corner of the App icons is very slightly more than it was before. Many icons, including a couple of our own, used the shape of the icon to their advantage - for example by placing the contents in a frame. It will be interesting to see how many icons are reworked for iOS 7,” she said. 

Will I need to redesign my app for iOS 7?

It’s not just icons that will need some attention in iOS 7. A number of developers are now faced with decision of whether to redesign their apps. Something many expect will be a time consuming process. However, our developers are happy to take on the challenge. 

Marketcircle CEO Alykhan Jetha expects that the redesign process will be challenging and time consuming for many developers. He explained: "Most apps have taken Apple's design language and derived from it. It took some time for developers to make that inspiration shine. It's going to be the same for this new design language." 

"It's going to be a challenge, but you can bet that we'll working extra hard to figure out how we can best leverage this new work and bring the benefits to our customers,” Jetha added. 

Readdle CEO Igor Zhadanov told us: “I love how Apple named it "polarising" during the keynote. The interface changes are significant, if not fundamental, so all developers will have to redesign their products eventually. The challenge though will be during the transition phase. Some users will prefer "traditional", iOS6-like appearance in the applications, while others will be looking for the new design. “

“This will fragment the market for some time (6-12 months) and will create extra pressure for developers. Besides, some of the developers we met are concerned about possible limitations of the new design language, i.e. whether it will be possible to build applications that are both compliant to the new guidelines and distinguished enough to stand out among competitors,” Zhadanov added.

Binary Formations’ Hamilton said: "The new look will be a larger factor for upcoming apps already in development or in the planning stages. For these, we will definitely want to adhere more closely to the design cues in iOS 7."

Hamilton added: "We do plan on taking advantage of some of the new capabilities in iOS 7." 

As Hamilton noted, it’s not just the new look of iOS 7 that developers need to address, there are a number of new features that they will be endeavouring to incorporate. 

Plastic’s Andrew Till expects that developers will plan to update their apps to take advantage of the new features available in iOS 7, or risk looking old fashioned. He said: “My first thought is that many developers are going to have to really step up their game to match the fluid animation in iOS 7. The transitions when opening apps, neat visual touches (bouncy speech bubbles when scrolling in Messages for one) and parallax wallpapers are all Apple on top of their game and I think most apps are going to seem very old-fashioned unless updated with similarly simplistic design and more dynamic animation.”

Developer Jonathan Teboul told us: “I will have to completely redesign my app. There are no longer bordered buttons, police fonts are thinner, status bars are gone, etc. Plus, I will have to handle new gestures as other built-in apps do.”

IGG's Gillespie has the same plans: “To look good on iOS 7, our apps will need some UI rework. Like many apps out there today, we've followed Apple's lead on previous designs: significant use of gradients, shadows and textures. Now most of that is gone, so we won't want our apps to stick out as antiquated.”

“We want to play nice with the OS so we can provide our customers with the best experience possible,” he added. 

The only problem with such a big change is that it will cost developers time and money to adapt to it, and as one developer pointed out, customers are not going to want to swallow that cost. CEO of Boinx Software Oliver Breindenbach said: “Of course customers will expect our apps to follow Apple's changes. It is great to see that after 5 years, iOS finally gets a refreshed look, but it also means a lot of work for developers that customers are not willing to pay extra for.”

Luckily it looks like the new features will be easy to integrate. MacAce’s Gary Hall told us: "I think many developers design there own iOS interfaces inline with Apple's in order to provide a familiar experience. The SDK makes that very easy so I would assume the new SDK and guidelines will allow many of these to automatically change with very little re-coding. As with all major updates though, we will be testing and tweaking things where necessary to keep thinks looking and working great."

Those who have created apps using tools provided by other companies may be concerned that their apps will not work well after the iOS 7 update. Quark’s Gavin Drake confirmed that anyone using App Studio to create apps need not be concerned…. “App Studio will support iOS 7 at launch. Once iOS 7 is supported, every app that is under a current plan will simply need to be recompiled at no additional cost and submitted it to Apple as an app update in order to have guaranteed iOS 7 compatibility”, Drake said. 

What’s iOS 7 like to use? 

Our developers have their hands on iOS 7, but they are limited as to what they can say about the new software without breaking Apple’s NDA. They were able to share a few comments about the features that impress them the most, however. 

“Finally, automatic updates. As a developer, this is a wonderful thing! As a user... I'm just glad it can be switched off,” said Bambu developer Andrew Till.

MacAce's Gary Hall told us: "From a user perspective, the control centre is the biggest useful feature for me as I can turn Bluetooth on and off easier." 

Hall added: "Multitasking will certainly help with the coding behind our syncing engine and preview/streaming capability - as these has been tricky to keep within Apple's guidelines." 

Till is intrigued by Apple’s new wallpapers. He told us: “One of our apps, Bambu, is full of art that can be used as wallpaper or greetings. The way wallpapers work on iOS 7 was obviously a big concern for us but it's impressively done – the text colour changes based on what will work best with the wallpaper, but it does mean high contrast wallpaper won't work well. One other issue is that wallpaper is zoomed-in slightly to allow for the parallax effect, so the quality of wallpapers designed to fit the screen is not quite as sharp as before. However, with the design so simple and colourful, the type of wallpaper really makes an enormous difference to how iOS 7 feels, and that creates an exciting opportunity for us with Bambu.”

Siri is still seen as a work in progress, although it’s beta status must be an embarrassment for Apple now. 

"Siri is still fairly closed in what it can do from third party apps, but we look forward to further enhancements here in the coming years - and the way we all want it to work probably is years away rather than months. Whilst eye-free car use is a novel idea - for the most part we all just end up shouting and swearing at Siri for not understanding us properly - perhaps an American accent would help?" said Hall. 

A couple of developers suggested that Apple had been adopting some of its new features from its WWDC audience. 

Breindenbach said: “It is unfortunate to see that instead of opening their APIs more for third parties, again and again Apple opts for taking good ideas from developers and integrating them in a less powerful form, taking away the developer's business foundation.”

Thanks to the following iOS developers for their help with this article: 

Binary Formations owner Kevin Hamilton
Keith Blount developer of Scrivener at Literature & Latte
Andrew Till director at Plastic
Greg Scown co-founder of Smile Software
IGG Software founder and president Ian Gillespie
Ray East marketing associate at BeLight Software
Public Space developer Frank Reiff
MacAce CEO Gary Hall
BeLight’s Viktoria Naumova
Karen MacLean of Open Planet Software
Marketcircle CEO Alykhan Jetha
Readdle CEO Igor Zhadanov
Developer Jonathan Teboul
CEO of Boinx Software Oliver Breindenbach
Quark’s Gavin Drake

Related: 

OS X Maverick: Apple's developers discuss Apple's new love for power users

Siri in iOS 7: Apple still playing catch up with Google, but moving aggressively

Apple iOS 7: Everything you need to know

Why iOS 7 will kill some apps (and make others stronger)

What does iOS 7 tell us about iPhone 5S, iPhone 6?

What people love about Apple iOS 7: review of reviews

What people hate about Apple iOS 7: review of reviews

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