Question to the pro's of syncing files between multiple android devices, NAS (Synology) + with a cloud storage on gmx.de
What App to use, how to set up.
Target use: I often add tags to pictures stored on mobile devices (android) and would like to have a updated master copy on my local NAS (when I am in my network) and a shadow copy in my cloud on gmx.de (processed by my NAS) and updated files on my other android devices (when they are in my network)