a mobile phone is not driven by hardware. its made gr8 by the softwarebit runs from.
well, first, forget nokia. microsoft is a botomless pit with snakes at the bottom. u wana avoid it at all costs. Installing whatsapp, or any app at all is a nitemare on a windows phone. and windows sucks on a PC. ten times more on a fone. and you wont have fun with your fone. windows is closed source.
on the other end of the spectrum is android. open source android. my phone, the S4 zoom, is a bit old now. but it runs a custom build of Android kitkat, (i coded most of the OS myself, save for the framework)
check out this article www.techradar.com/news/phone-and-communications/mobile-phones/best-android-phone-which-should-you-buy-717819