My sister, sister-in-law, brother-in-law and three close friends all use iPhone's. Ironically, in my small circle, iOS is the most commonly used operating system. When I first encountered iOS in iPhone 3G, I found it very interesting. But back then, I still regarded touchscreen devices as more gimmicky than a tool and paid it little attention. In the almost three years since then, I myself have migrated to purely touchscreen devices, and see no reason for a physical keypad ever again.
User friendly. One thing I noted about iOS users is that they have no complaints. They either love it, or say, well it is just like any other phone. The latter response comes from two users who use it mainly for calls and text, and do not really take advantage of smartphones in general. When I took a closer look at iOS last year, it took me just a few minutes to get used to it. If you have used a Macbook, everything will look familiar. If not, you will feel comfortable in a few minutes. I asked a friend of mine who is an iOS power user if he has ever had to "Google" anything (search for how to do something). He only had to do so once, to find out how to take screenshots. Basically, the interface is so well designed that no instruction manual is needed.
The iOS interface does not appeal to me for only one reason, the inability to display my next calendar entry on the home screen... a feature I have come to depend on since my old Microsoft powered HTC Tanager back in 2003. For me, that is a deal breaker. For those who do not look for that feature, iOS may be the ticket for you.
For anyone who use a computer, the iOS interface will look familiar. The "desktop" is filled with icons. Notifications either appear on screen or as an red indicator with a number on the icon to alert you to things which need your attention.
If you receive a new SMS, you can even read the message without having to unlock the phone.
Apple iOS has up to eleven home screens which can be accessed by swiping left or right. You can customize the interface by moving icons around up to eleven home screens and replace the four icons on the dock which appear at the bottom on all the home screens. Icons can also be placed in folders. It is a very simple, intuitive user friendly system, which is challenged only by Windows Phone 7 in ease of use.
Apps. Apple has the biggest apps store. Over 300,000 apps. Apple also designs their own hardware and regulate the apps in their app store so, compatibility is not an issue. Basically, everything just works. This is an issue which we bundle together with the user interface since, efficiently running apps is one of the main purposes of the user interface. Also, unlike the Android and Windows apps stores, you can buy paid up from the Philippines. The other apps stores only allow Philippine users to get free apps.
Weaknesses. The icon driven interface means a PC like experience. The one which bugs me the most being the absence of informational widgets on the lock screen or home screen. One to check on your next appointment, you have to launch the calendar app. It has no quick toggles for Wi-Fi, Bluetooth or 3G, so if you want adjust these settings, you have to go into the settings application. Basically, it forces you to dig into one or more layers to get the information you want.
Other than this, iOS does have other drawbacks. It does not have true multitasking for all applications, no proper file browser or access to the file system (this problem is compounded by the absence of the USB mass storage mode, so basically you are completely dependent on iTunes for file management) and lacks flash support in the web browser. For those who like videos, note that there is no support for DivX and XviD and no official third-party application to play these formats.
Basically, it has a nice, intuitive user interface, with problem-free application compatibility. I do not think any user would hate it. It works. Techie types looking for more control over the interface. "Power users" may want to look somewhere else though.
You can of course jailbreak your phone, but we really cannot recommend that.