Having now developed apps for both iPhone and Android, the one thing I feel Android really lacks is a good equivalent to Apple's Interface Builder.
Interface Builder makes it pretty easy to lay out a decent-looking app GUI on iOS and not have to think about it a lot, so you can focus on the code and functionality of your app. It takes more effort while writing that XML on Android to end up with an attractively designed interface, and short of running it in several different emulators it's tough to get an idea of what it'll look like on different devices in terms of display resolution and dimensions.
Interface Builder makes it pretty easy to lay out a decent-looking app GUI on iOS and not have to think about it a lot, so you can focus on the code and functionality of your app. It takes more effort while writing that XML on Android to end up with an attractively designed interface, and short of running it in several different emulators it's tough to get an idea of what it'll look like on different devices in terms of display resolution and dimensions.