Expanding my smartphone's RAM

[Jomjom]

Hi guys, I just want to ask if it's really possible to expand my phone's RAM up to 4gb? I heard a month ago about an app that is capable of expanding a phone's RAM, but I hesitated to download the app for fear that my smartphone might crash. The problem is from time to time, I had to delete something in order to accommodate new files download new apps. Let me know your thoughts, guys.

By the way, my phone's Lenovo a7000, having a 2gb RAM.