Display multiple app screens at the same time
If you have a Samsung phone, there is a split screen option. I personally have not used it, so you would have to look into it. The option is not available as stand, no.   

There are some third party ROMs, that are capable of doing it but you would need to root your phone.  Have a look at the link below. I had a quick look out on the web and found this:
How to Get Multi-Window Multitasking on Any Android Phone or Tablet