I have a book (one of the thousands) that deals with the Third Reich.
Of course the German national flag during the Nazi years was the plain swaztika type, however, the Germans apparently had a real fetish about flags.
There was one for almost every branch and unit of the Party. There would be at least 50 different flags listed for one organisation or another, ie the SA has theirs, SS had theirs, the Luftwaffe had theirs etc.
They all seem to be based either on the swaztika or the 'maltese' type cross, or both.

Here are the 'State Flag' and 'War Ensign' respectively:

