Thanks guys for the help. I did install and activate it and rebooted. I activated the greenify module and rebooted again. Then I turned on the "keep notiifcations" feature in greenify and rebooted yet again. Now another problem quietly bombarded upon my face. I am simply not getting any notification for the hibernated apps. For example, let's take the Facebook's messenger app. It is hibernated. I asked my friend to send me a message just to see if I got any notification. I simply didn't. Any solutions to this?