'Virtual Application'-like Function


I would enjoy an option to 'clone' certain applications - say, a web browser - and run it as a separate, distinct application that's password protected. 


I like the idea of the File Vault, but I'd rather not enter my password every time I want to make a quick Google search. 


 Say we have the Firefox web browser. Imagine that I am concerned about privacy - say it's a shared computer, or I'm just not comfortable having certain things easily accessible on my browser. I want to still have my cookies and bookmarks and data, but I want a password protected version that is separate from the original. 


I'm proposing there is the main application - imagine Firefox once more. Then there is the branch application - fully functioning, everything from the original browser is synced with this one, except the branch is both password protected and encrypted as well as separate - there is data flow from the original application to the branch, but not vice versa. This way, you can still have all your history, bookmarks, everything easily accessible from the branch browser, but don't have to worry about clearing history or cookies or anything. 


You could do this through maybe a virtual machine, or just a clone program. I don't know, but I would love to see this integrated and accessible in the application. 


I'd enjoy it on Android too - it'd be similar to Samsung Knox.