In-depth Review: Apple's iOS 5 mobile operating system
Camera and AirPlay video output
While iPhone 4 delivered a good camera, under iOS 4 it is a bit of a pain to rapidly launch the camera app to snap a shot. In iOS 5, double clicking the Home button presents an alternative lock screen with quick access to audio playback controls and the camera. Tap the camera button and you can capture pictures without unlocking the device with your passcode. You can now also use the iPhone's volume buttons to snap a photo.
That special mode restricts the user from doing anything apart from capturing pictures, but it finally makes it possible to quickly capture something without navigating through a login and manually launching the Camera app. You can now also use the volume up button as a shutter release, which often works much better than trying to tap the software button presented on the screen.
Once you take your pictures, you can display them on your HDTV, wirelessly, thanks to AirPlay. Video, slideshows and any games and other apps that support VGA or HDMI output should also support AirPlay wireless video to Apple TV. Additionally, iPad 2 and the new iPhone 4S support wireless AirPlay Mirroring of the entire screen from nearly any app, making it easy to show off what you're doing via a big screen during presentations or in front of a class.
Safari and Siri
What does Apple's open source web browser and its entirely proprietary new artificial intelligence engine have in common? Absolutely nothing, demonstrating the range of new features iOS 5: on one hand, it breathes life into existing phones, including the iPhone 3GS Apple first shipped back in the summer of 2009 and the original iPad from the spring of 2010.
Safari is a great example of that, delivering a major boost in speed, new features such as the Instapaper-like Reading List of articles you want to bookmark and (for iPad) tabbed browsing. It's useful to note that fairly new phones and devices are not getting similar attention from competing platforms. The original Galaxy Tab, for example, didn't get Android 3.0 Honeycomb despite being just a few months old when it arrived. In general, Android phones don't get updates for 3-6 months after they're released, if ever.
On the other hand, iOS 5 also delivers functionality that's only usable on the new iPhone 4S, particularly Siri and its new faster camera. Despite spanning three generations of smartphones and two generations of iPads (and iPod touch), Apple has delivered a platform that doesn't introduce significant app fragmentation issues for users and developers because of the work done to abstract differences in hardware.
Users don't really have to think about the specific OS version their app was created for, don't have to think about the processor in use, and don't even need to worry about how to sync documents, purchased content or photos between devices. iOS 5 does a great job of improving things in ways that don't introduce new problems.
iOS 5 is the latest example of Apple delivering software to power hardware with an abstracted layer of usability that just makes sense. There's no required skills in computer science needed to kill of offending apps to make the rest of the phone work acceptably fast or to prevent the battery from running down, and no need to worry about virulent malware or legitimate looking apps stealing your data and forwarding it to a foreign server.
Room for growth
Apple has put a lot of sophisticated engineering into iOS 5, but there's still areas to work on for next year. It appears that as the installed base of iPhone users incrementally gets faster, iOS will be able to begin taking on more tasks and perhaps easing up on multitasking restrictions intended to save battery, allowing users to, for example, switch between apps faster.
Additional services may be integrated into iOS in the way Twitter has been, potentially allowing third parties to tap into shared web services. And we have only just begun to see what developers can do with iCloud.
Once memory and processing power reach a certain threshold, iPhones and iPads will be able to perform more sophisticated imaging functions, mimicking more of the functionality currently stuck on the desktop. There's also a lot of little enhancements Apple could add, such as making it easy to attach photos to emails being composed, or to share files with AirDrop Macs or WebDAV file servers.
All in all, however, iOS 5 erases the top few remaining features that rival platforms could previously claim as unique, while bolstering Apple's own proprietary advantages with iCloud, iTunes and the App Store, three critical areas its rivals seem both incapable and uninterested in even attempting to match.