The user interface found on the iPhone 4 is largely unchanged, but there are some new additions and improvements to point out. There's a new name--iPhone OS4 is now called iOS 4--and a new level of customization to the system. The name change foreshadows that the OS won't always be used on smartphones alone, with the iPod touch, iPad and possibly even more devices to support the software in the future. It's a stup up from iPhone OS 3, and Apple has chosen a powerful device to showcase it.
The new A4 chip is powerful enough to handle the new changes, with the primary addition being the innate ability to multi-task. But multi-task is a word that is broadly defined; we would say that the truth is that iOS 4 now supports "background tasks." There's no true multi-tasking when you can only view one application on the screen at one time, and processing isn't always going on in the background, but you can run apps in the background while another runs in the foreground. For example, Pandora can stream music in the background while your surf in Mobile Safari in the foreground. But to change playlists or genres in Pandora (unless they're next in your lineup), you have to actually get out of Mobile Safari and back into Pandora, which explains our defining of the situation as less multi-tasking and more "background tasking."
Either way, it's a big change for Apple, and it's something that was badly needed. Android has supported background tasks for well over a year now, and Palm's WebOS and Windows Mobile have as well. Apple was falling way behind in this department, and they had little choice but to finally play catch up. As they did with copy-and-paste, though, Apple has done a good job with the implementation. A simple double-tap of the Home button brings up a row of four icons along the bottom, allowing users to hop out of one app and into another without having to fully exit to the desktop. If you have ever Jailbroken your iPhone or iPad and used "Backgrounder," this new official Apple multi-tasking solution works almost exactly like that. But of course, you don't need to Jailbreak your phone now to do it.
Apple claims that 1500 new features are being added to iOS 4, but only 100 of those are designated as "user features," while the others are developer features. That's probably a gross exaggeration; "hundreds" of new features were supposedly baked into Snow Leopard, but many average users won't find but a handful that they notice and make use of. The rest of the changes are so subtle that they aren't worth mentioning. A few of the changes worth mentioning are this: a unified inbox (which groups your e-mail accounts together in a logical way so that you only ever have to view one e-mail box), app folders (which allows you to group all of your social networking apps, for example, into a single folder rather than taking up an entire home screen page), Bing search integration, in-app SMS, spell check, Bluetooth keyboard support, user-defined wallpapers (finally!), iBook support, enhanced Enterprise integration, and a Game Center that is basically an Xbox LIVE clone with achievements and the like.
A few of the more subtle changes that will still definitely improve the user experience are: background audio (for streaming Pandora in the background), background VoIP (for using Skype while browsing the web or checking your e-mail or playing Plants vs. Zombies), map overlays, and background location data for keeping tabs on your location in Maps while you do other things in the foreground. Apple has also enabled Tap To Focus on the camera and HD video editing on the phone itself. There's also a little thing called "task completion," which is very much needed. This enables lengthy tasks to continue to run and process in the background while you take on new tasks in the foreground; for example, if you have a lot of images uploading to Flickr, you can now leave that running in the background and move on to playing a game or composing a note. The images will continue to upload in the background, exactly like they should.
We mentioned it earlier, but the ability to Tether is also now included on iOS 4. AT&T has finally added support for this in the U.S., but a new data plan in required in order to take advantage. As with most everything else that Apple has implemented within iOS 4, Internet Tethering is seamless and easy here. Once you've activated it within Settings, a Blue bar remains at the top of your screen in order to let you know that it's active. Phone calls and phone data are both still available even with Tethering active.
Those are the changes, and we have to say that Apple has done a good job of integrating these new features into a familiar user interface. Users of existing iPhone models won't notice much of a new learning curve. In fact, you can use iOS 4 just like you have used iPhone OS 3, and you'll get along just fine. But the new features are super easy to discover and get used to; the only thing you need to do in order to start enjoying multi-tasking is double tap the Home button. Pretty simple. Most everything just happens in the background and works for you, rather than forcing you to work for it. That's the biggest change in our opinion; iOS 4 is better designed to fit into your workflow, instead of you having to force yourself to change your workflow in order to work with just a single app at a time.