Run Multiple Android App Instances Like Parallel Space

I want to know how parallel space https://play.google.com/store/apps/details?id=com.lbe.parallel.intl&hl=en is working. It is an app for logging in with another facebook, what

Solution 1:

Actually they have created a virtual OS named multi-droid where you can run any app on that OS. As you install any app on their OS the space for that app increases by the size of the app. Firstly they find the path of your installed APK then they copy that APK into somewhere in the directory Thus they have the APK to install . now they run it on their OS and they took all the permissions required by the app that way all the permission could be obtained .then the app has a service running in background so notifications can be obtained .