The flat is very close to one supermarket and there are more only a bit further away. Additionally there is a convenience store right around the corner where you can get some milk even late on Sunday.
Several restaurants are even closer.
You get to U Nollendorfplatz easily, as it's just a 5 Minute walk along Motzstraße.
What Rainer has to offer here is a very nice place where you can stay comfortably right in the middle of the gay area in Berlin. You would surely notice that when you see the display windows of some special shops nearby.

Thanks a lot for hosting me,
cheers
Birger!