@abcdw
1. Organic Maps (Or OSMAnd if you are carto addicted, it has much more features)
2. stock calendar + DavX (sync with nextcloud cals)
3. stock keyboard is enough for me
4. AntennaPod (for podcasts), NewPipe (for peertube / yt videos)
5. Sorry I don't use audio books
6. Nextcloud (Hetzner has a very nice all-included service offer available at https://www.hetzner.com/storage/storage-share)