CPU-Z is one of the useful application for those who wants to know in about phone in depth. I am using this app for a long time in both my Android device and Computer and I have very good experience with this app.
It gives me all the software / hardware detail of my phone like processor, cpu, gpu. which is not specified in about phone section.
One more special thing is this app is, it shows you root access and bootloader type detail. To check only root access we generally use different apps like root checker .
Thanks!