In Depth: Hands on: iOS 4.2 review

Apple's iOS 4.2.1 update for its mobile devices arrived on 22 November 22 and we've been trying it out.

If you've not yet installed the update, ensure you first do a manual back-up of your stored back-up files, in case of problems. Apple provides the locations of said files in a technote.

Catch-up for iPad

Although iOS 4.2.1 brings updates to all iOS devices, the iPad benefits most, finally catching up with the iPhone and iPod touch in important areas such as multitasking and folders.

Multitasking works as per Apple's smaller iOS devices: apps are 'paused' in the background, bar Apple-approved tasks (such as playing audio); a double-click of the Home button brings up a multitasking bar, enabling you to switch apps or tap-hold to access quit buttons; a left-swipe of the multitasking bar provides access to iPod controls and the orientation lock.

The main advantage the iPad brings is in providing brightness and volume sliders in addition to the iPod controls; you also get more apps in the multitasking bar (six in portrait, seven in landscape).

Annoyingly, the orientation lock is now the only mechanism to stop the iPad's twitchy accelerometer from rotating the screen when you're using it - Apple has turned the easily discoverable hardware control into a pointless mute switch. On the plus side, while multitasking initially made our test iPad feel sluggish, everything was fine after a reboot.

MULTITASKING: Multitasking comes to the iPad, but the orientation lock is now software-only

Folders work as per the iPhone - drag an app icon on top of another to make a new folder. The iPad again makes use of its generous screen space, enabling you to store 20 apps within a single folder.

Since folders can be placed in the iPad's six-item Dock, this potentially provides rapid access to 120 apps from any Home Screen page. As on the iPhone, folder icons display miniature icons of nine enclosed apps.

NEW FOLDERS: Folders on the iPad can store up to 20 apps

Along with Mail's unified mailbox, this update brings Game Center to the iPad. The back-and-forth nature of Game Center navigation is awkward and annoying on the iPhone, but on iPad the spacious two-pane layout makes it simple to compare scores with friends. Additionally, iOS 4 on iPad means your scores are now accessible and saveable for Game Center-compatible universal apps on any device you're using.

GAME ON: Game Center for iPad makes good use of extra screen space

Cross-device updates

The biggest two updates for all iOS devices are perhaps the most disappointing. AirPrint initially promised printing to compatible and shared printers; but support for the latter recently vanished, leaving AirPrint currently compatible with only a handful of HP printers.

This is a pretty pathetic state of affairs, and Mac users for the time being should seriously consider Ecamm's excellent Printopia for sharing printers to iOS devices. Windows owners should instead march on Cupertino.

AirPlay is also problematic: while it largely works fine for streaming content from Apple's own media apps to the Apple TV, it's audio-only for (some) third-party apps, and it's unknown when or if this situation will improve.

A major update that isn't a disappointment is Find My iPhone. This free universal app works in conjunction with iOS 4.2.1 and a free MobileMe account to provide location and remote-wipe services for your iOS devices - things that previously required a fully paid $99 per year MobileMe account.

Apple's wording regarding support isn't entirely clear, suggesting the service only works with its latest devices. However, you instead need - for some reason - to use a 2010 iOS device to create the free MobileMe account, after which point you can add whatever devices you like.

For example, we got everything working fine on an iPhone 3GS. (Ironically, the terms and conditions Agree button twice crashed the Settings app on our iPad, but all was fine post-reboot.)

FREE TO FIND: Find My iPhone, working on our iPhone 3GS - for free

As with Snow Leopard on the Mac, it's actually many of the smaller tweaks that turn iOS 4.2.1 into a success. For example, if you regularly hand your device over to a devious toddler whose favourite game is 'delete all of daddy's apps', you can now lock down app installation and deletion (along with Game Center requests and, importantly, in-app purchases) in the Restrictions portion of Settings.

We're not sure how discoverable this feature is (our guess: not very), but when unearthed it's easy to use and intuitive. Just make sure the Mini You doesn't figure out your four-digit passcode…

SAFE: If your toddlers delete all your apps, you can now disable app deletion in Settings

Elsewhere, Notes gets a choice of fonts (the hideous Marker Felt, the hideous Chalkboard and the non-hideous Helvetica), Photos enables multiple-item selection prior to a share (seemingly restricted to five items on our iPhone 3GS, but not on the iPad), you can define specific ringtones and SMS tones per contact, and Safari gets enhanced sharing options and in-page search.

The share button replaces the old '+' bookmarks one, and essentially adds access to AirPrint, and so it's unlikely to be of much use to many until Apple 'unbreaks' that feature. In-page search works nicely, despite the bonkers workflow - you use the search box (yes, the one marked 'Google') and if any in-page matches are found, the last option in the list tells you.

Tap it and the first instance of your term is highlighted. You can then use the Next button to access more matches, or, on the iPad, start another search by using the toolbar's built-in search field. The workflow and baffling lack of a Previous button suggest this is very much a 1.0 (or, perhaps, 0.1) version of this feature, but it works well enough, despite its quirks.

NEW BUTTON: Safari gets a new share button; on the iPad, the number of open pages is now also displayed

Future plans

Apple of course remains tight-lipped about future plans for iOS, but numerous features remain notable by their absence: a decent notifications system; wireless sync; multi-user capabilities; no streaming media to your iOS device from a networked Mac or PC.

Despite these shortcomings and AirPrint and AirPlay being less than hoped for, iOS 4.2.1 is a must-have upgrade for iPad owners.

For iPhone and iPod touch owners, the reasons for upgrading are fewer, but the revisions still make iOS 4.2.1 compelling, since you're getting improvements for no investment aside from a little of your time.