I use a popular app called readera to read and manage ebooks on my android smartphone.
I want to have all the ebooks on a 2TB portable harddisk that remains connected to a raspberry Pi at all times. The pi could be running on "Ubuntu 20.10 for raspberry" which in turn runs Anbox which in turn runs the readera app. And finally I could use a VNC server on the pi to view the "remote" app on my smartphone's VNC client as if it was running on my own device natively.
There seems to be several other ways to get this done. For instance using emulators other than anbox or running an android OS directly on the raspberry Pi etc. Can anyone offer any suggestions? Am not looking for a NAS storage type solution where only the data is remotely stored and apps are on the user's side.