What is considered a good GPA for studies in Germany Coming from a different schooling/grading system, I have very little feeling about what actually is considered a good grade for studies in Germany.

Here the passing grades are given in the range of 1.0 to 4.0 and there are non-passing (failing) grades, which basically tell how hard you failed.
Needless to say, 1.0 is the best possible and tells that the student performed perfectly, but what about the other grades. What does 2.0 mean? It is translated as "good" but is that average actually. How does the teacher/professor "see" that grade.

Moreover, what is the typical GPA average which gives a student a chance to be considered for a Phd position? Of course, the higher the better, but what gpa (in the german grading system) would be considered OK-ish for a phd application?
Given that "grade inflation" is often much less rampant in Germany than in other nations (it is not unusual, for instance, for the majority of students to fail an exam in a core subject), the standards inside of Germany tend not to be as stringent as in other places I've seen. For instance, anything better than 2.0 (on a 5.0 scale, not a 4.0 scale!) would generally be considered "competitive."

Obviously, there are limitations—if you get a 2.0 because you've gotten 1.0's in the general courses and 3.0 in the courses in your subdiscipline, you're not likely going to be an attractive candidate to an outside group.

However, I think much more important than the exact GPA is the quality of the master's thesis. If you have a very strong master's thesis, you will likely get some interest from the group in which you did the thesis work to continue on for a PhD, if there is an open position available. A weak grade on the thesis (anything below a 1.3) usually is a sign of substandard performance, which is likely to result in not being considered for a position, even if your GPA is a 1.1 or 1.2 (it's unlikely to be a 1.0 under such circumstances).