For a long time I was struggling with very slow Android emulators. Actually, it was impossible to work comfortably with using them, so most of tests I’ve performed, were on real devices. Of course, I can’t test mobile application on every of thousands mobile devices which runs on Android system. Some time ago, I tried to do some experiments with running Android as a virtual machine on Virtual Box. It was faster than emulators provided with SDK, but still, it was slow. Recently I’ve found Genymotion project. Actually Genymotion provides virtual machines with Android OS, which runs with Virtual Box. It seemed to be the same solution I’ve tried before, but it provides all-in-one package with optimized images of Android OS and predefined configurations of various devices. It’s nothing special. One thing, which truly amazed me, was the speed of this emulator. It is really fast! Actually it runs as fast as Android OS on real device! With such tool, debugging with emulator finally makes sense and can be comfortable. One of the useful features is the possibility to attach real device, pass data from its accelerometer to the computer and emulate it on virtual machine. You can use it for free for your personal use with basic functionality. If you want to use it for commercial purposes or you want to have additional features like recording screen casts, then you have to buy the license. You can also install IntelliJ (Android Studio) plugin, which integrates Genymotion with your IDE.