The best way to preview your forms is to simply open the form on your mobile device. However, if for some reason you do not yet have access to a phone or tablet, there are many available Android emulators out there that you can use to test Magpi. Genymotion is one such emulator which we can recommend.
Genymotion provides many virtual devices/emulators to select from, so you will experience any app as if you were using an actual Android device. Once you have installed Genymotion, just drag and drop Magpi apk file to it, and it will be automatically installed.