Content Server for any device with a Web Browser
But wait! There is more
That is easy-peasy for a local (w/WiFi) network: (The sharing Icon): Start the content Server
From outside requires Opening a pinhole in your router and that is a Security Bag-o-worms. Also, the exact way is router dependent and a whole lot of net working stuff.
For Android Devices: Calibre Companion along with a Commercial Cloud like Dropbox (see CC FAQ for supported clouds)