If the developer states that they are not confident with specific functionality of the app, then this is an area that should take most of the focus of your testing. Lack of confidence from the developer should also trigger in your mind that significant testing is required throughout the app, and not just on the areas of concern.
The new Android platform is growing by leaping and bounds everyday and many website applications developers are creating iPhone apps but also latching on to the android platform. One of the drawbacks to the Android platform early on was that the Apple App Store dwarfed that of Android but over the recent months more and more Android apps are becoming available and Android is actually taking a decent portion of the market back from Apple.
Operating system: iPhone OS-Derived from the Mac OS X, shares the Darwin foundation. The OS has four abstraction layers, the core OS layer, the core services layer, the media layer and the cocoa touch layer. The OS uses less than500 MB of the device’s memory. Unable to multi-task.