I been searching the internet to find out how much memory does iOS9 use compare to iOS8. If it's more, I would rather pass as I have almost no memory left on my phone. I understand that iOS8 took 4+GB to install and iOS9 only 1GB but I'm not sure if that the same amount after installation. Does anyone know? I would like to upgrade to iOS9 if it means I get back 3 GB that IOS8 used.