Android apps still run quite slow on the x86 Android emulator. I suspect that this is because CPU emulation is only one part of full emulation of an Android sys

Android apps still run quite slow on the x86 Android emulator. I suspect that this is because CPU emulation is only one part of full emulation of an Android system. When running Android apps using the Chrome runtime, apps run blazingly fast, since it just calls directly into the native OS / the Chrome runtime for any native acceleration feature it requires. It also doesn't run in a full-blown virtual machine as the emulator does. As the other reply points out, the iOS emulator also doesn't emulate a full system. It just runs the required iOS APIs directly on OS X, just to give you an idea of a running app and the progress you're making on a feature. Again, for most development scenarios that is really all you need (and you use an actual device for more thorough testing or when you need hardware features).