Excuse me, of course:
I will look up your suggested apps.
edit: I have seen the apps through, but root is no option for me because I've already tried and failed the root access. I think, I've done some damage and therefore would like to reset this phone.
2nd edit: I found an app called Helium that does it. There I can back up single apps into files which I can later extract from my internal memory to anywhere I want. The directory of the internal memory to where Helium saves the back up files is called carbon. Thank you for everything .)