Which Apps fill my RAM with Garbage (only 35Mb of 2Gb is free, extrem slow iPhone)

Hello

My iPhone has 2Gb of RAM and 128Gb of FlashMemory

Memory & Memory isn't the Same! Apple only spoke about the FlashMemory! Nobody speaks about the RAM. ?!?

The iPhone has about 70Gb of free FlashMemory which I can view in the Settings/General/iPhone Memory

My iPhone is getting so slow an a dozen of apps can't even open! (e.g. CNN)

I want to know which Apps filling my RAM, so that I will delete them

With "Smart Memory Pro" I was able so see I have only 35Mb of 2Gb is free, but this App doesn't tell me which fill my RAM with Garbage and give I free after I "killed" the Apps, more than once a day!!!

Is there a tool availible?

Regard

Gérard