Apple iOS 4.3

The latest revision of Apple's mobile operating system, iOS 4.3, sneakily arrived on 9 March - a couple of days before its official release date.
As with other versions of iOS, many of the changes are minor, but there are nonetheless fairly major updates to Home Sharing and AirPlay, along with the introduction of a long-awaited personal hotspot feature.
Naturally, the release also retains revisions included in previous versions of iOS 4.x, such as multitasking, springboard folders, Find My iPhone, Game Center and enhanced Mail.
Home Sharing
Since iOS devices have utterly fixed storage, they are restrictive for anyone who has a large media library.
Even the iPad 2 won't assist on this score, since it tops out (like the current-generation iPod touch) at a mere 64GB of storage (several GB of which is taken up by system software). This forces a pick-and-choose approach to media-syncing, but iOS 4.3's Home Sharing provides a logical and flexible alternative, streaming media from a Mac or PC on the same Wi-Fi network as your device.


HOME SHARING: this new feature enables you to play iTunes content from a Mac or PC on the same network as your device
In use, set-up is simple, as outlined in TechRadar's Home Sharing tutorial, and playback appears efficient and robust. Our test Mac's relatively large media library, with over 90 GB of music, didn't cause crashes or lock-ups, and the library loaded in around ten seconds; subsequent audio playback was instantaneous, and switching between a remote and local library is child's play.
Video is less impressive, since it's slower to begin playback over a network, and Apple's Videos app is bare-bones and buggy; during testing, it regularly forgot to apply thumbnails and titles to videos it found in a remote library.

VIDEOS: The Videos app proved buggy during testing, with both Home Sharing and AirPlay
It's also worth noting that the revamped Home Sharing feature is not in any way a sync solution—presumably, wireless sync is still slated for a future version of iOS.
AirPlay video
The second major plus introduced in iOS 4.3 is AirPlay video support. In iOS 4.2, this feature was hobbled and only worked with a very limited number of built-in apps (iPod, Videos, YouTube); in iOS 4.3, it's open to third-party apps and other Apple software, including Safari and Photos.
This was the feature Apple TV 2 users were most looking forward to, since it promised a means of unlocking the potential of a device starved of media (at least for anyone outside of the USA). In practice, AirPlay is a step forward from the version in iOS 4.2, but it's not without its problems.

SAFARI: You can now play Safari videos on an Apple TV
On test, we found using AirPlay video fell into three camps: 'great', 'problematic' and 'the BBC'.
Videos and slideshows from the Photos app played flawlessly on the Apple TV (once its software had been updated), as did on-device content, videos from YouTube, and videos in Safari that use the standard iOS player.
Bandwidth issues made playing back network video problematic: the Videos app just threw up error messages, while playback using the Air Video app was a lottery—some formats live-converted and played back fine, whereas others (notably MKV files) needed buffering at regular intervals.

iPLAYER: Want to watch BBC content on your Apple TV over AirPlay? Tough
And then there's the BBC: its apps (and even the iPlayer website) don't work at all with AirPlay. This isn't Apple's fault, since the BBC eschews the default player, but it's a pity there's still no way of getting iPlayer and BBC News on to your TV via the Apple TV. Here's hoping the BBC updates its apps soon.

Hotspots, Safari and Settings
The third and last of the major updates in iOS 4.3 is personal hotspot, an iPhone 4-only feature that enables the device to act as a Wi-Fi router for other devices (three over Wi-Fi, and up to two more via USB and BlueTooth).
This brings iOS into line with Android's Mobile AP feature, and it appears to 'just work', but note that you need a qualifying data plan or risk being charged unexpectedly.
Best of the rest
Most of the other changes in iOS are relatively minor, but nonetheless welcome.
Safari's JavaScript performance is noticeably faster—handy for a device more reliant than other platforms on JavaScript-heavy interactive web content (as opposed to Flash).
In Settings, a rare Apple about-face enables you to define whether the side-switch on the iPad locks rotation or mutes the device (hurrah!); muting also remains available in the multitasking tray and by holding the volume-down end of the volume switch for a second.

SIDE SWITCH: The rotation lock is back! And all it took was a ton of bitchy emails to Apple!
You can now set the number of times a Messages app repeat alert sounds (once, twice, three, five or ten times), find Location Services at the top level of the Settings app, and use the new Noteworthy font in Notes (but not Chalkboard, which has been taken out back and shot).
Apple's also not entirely forgotten Ping: select it in the iPod app and you'll be asked if you want to be bugged with notifications regarding comments and follow requests.

PING: Now slightly less useless (i.e. still useless)
Apple also claims you can 'like' songs from the iPod app's Now Playing screen, but if this is the case, there must be some kind of ninja-style protection, because we couldn't find the controls on any of our iOS devices. Fundamentally, Ping still seems broadly useless.
Omissions and mothballed kit
Of course, it wouldn't be an iOS review without some gripes about what Apple didn't include.
AirPlay might have received some love, but AirPrint remains half-baked, working with only a very limited range of printers. It's a pity Apple doesn't enable you to print to shared network printers.
Also, the iOS notification system remains intrusive and generally awful, and fancy new multitouch gestures splattered all over the rumour mill during iOS 4.3's beta run remain off-limits unless you're a developer.
While some of these would have caused pain to developers, clashing with existing software controls, a fast means of app-switching would have been useful for power users.
This update also unceremoniously officially mothballs the iPhone 3G and second-generation iPod touch.
Given how rough iOS 4 has been on these devices from the start, this comes as no surprise, but it will disappoint users to learn devices that are under three years old have hit a software brick wall.
For the rest of us, iOS 4.3 is a no-brainer upgrade. We tested the system on an iPhone 3GS, current-generation iPod touch and an iPad and it seemed both solid and stable, and it's clear that Home Sharing and AirPlay will further open up the potential for iOS to become a leading platform for media playback.