Project Gutenberg Canada has a few that fall under Life+50 rules and some are old enough to be Life+70 if that's your eligible region instead.
And here are a short-ish listing of freely offered German PD ebooks at
Ebooks.au's multilingual page (no direct link to each language; you'll have to scroll down or do a "find" since some are multi-language-hosting sites), and a longer
list of links to German ebook and online literature sources at the Multilingual Books page.
And we've a good number of German-language classics right here in our
Patricia Clark Memorial E-book Library. Just go to the search and type in "German" or your favourite author to see what comes up.
Hope this helps, and welcome to MobileRead!