Hello people, I need to ask the swarm intelligence for some suggestions for my problem:

I am hosting my eBooks and some downloaded research papers (best idea ever btw) on a calibre instance at home. My gf loves to listen to audio books and it seems like calibre has support for them as well (did not test that yet). Now I need an Android app, preferably open-source, that can connect to calibre and pull and play audio books and ideally also ebooks in case she wants to read. For me, KOReader does a decent job but the audio book part is sth I was unable to solve so far. Does somebody have a similar use case and solution? Thanks in advance!