Highly reliable, secure, and stable. A number of tools for programmer’s support in coding.
What is most valuable?
* Well documented SDK.
* Highly secure, since all apps run sandboxed.
* Applications are highly stable.
* Abundance of resources and tutorials are available on the internet.
* Lets you access iOS core services, core services being networking and threading.
* Integrated support OpenGL ES 2.0 (OpenGL framework is used in games on iphone, ipad and ipod touch).
* Media support, iOS offers great flexibility for performing operations on audio, video and picture.
* Multi-touch support. Lots of in built touch gesture recognizers, which a programmer can use to make an app quite impressive.
* Xcode provides instruments that give you a better insight of your code, especially about memory management, if you are using MRC(Manual Refrence Counting).
* ARC (Automatic Reference Counting), introduced in iOS 5, is a great feature for programmers who are sloppy with memory management concepts.
* Usage of other languages like c. iOS uses objective c basically, but you can also use your existing c code within your iOS prgram with no extra effort. The compiler changes that c code into objective c code while compiling.
* GPU is available so that applications not built with OpenGL can still make the app rendering process faster.
* Single application for all the 3 device types, by making a universal application (iPhone, iPod touch and iPad).
* iOS SDK is also open source licensed under MIT.
What needs improvement?
* A Mac is required for developing. Development is strictly restricted to Mac.
* Flash or shockwave videos do not run on this platform.
* ARC is not helpful in scenarios where you need control over the memory.
* Restricted to Apple devices.
* Subscription to developer program is yearly.
*Disclosure: My company does not have a business relationship with this vendor other than being a customer.