I need to develop an app for iPod. The latest version I can upgrade the iPod is iOS 4.2.1. I'm currently using Xcode 4.2 and the oldest simulator I can get it run is 4.3.
If I debug using 4.3 simulator, will it be safe for iPod iOS 4.2.1? Or how can I get the 4.2 simulator?
unfortunately, there's no way (that I know of) to download the older versions of xcode and the associated simulators. Strictly speaking, the answer is no, it won't be safe unless you test on an actual device running that OS version ... but the more complicated answer is that it will run, you just have to be careful.
You will hear this echoed in many other responses here on SO on the topic, but you should generally build against the latest SDK version (in this case xcode 4.2), but set the deployment target to the lowest value you care to support. You will of course have to make runtime checks for APIs that may or may not exist on older devices (respondsToSelector).
