I'm trying to tackle this problem here (as in, just starting up again after brief hiatus): https://github.com/atomirex/umbrella https://github.com/atomirex/umbr

I'm trying to tackle this problem here (as in, just starting up again after brief hiatus): https://github.com/atomirex/umbrella https://github.com/atomirex/umbrella My approach is to store files in a (J)Git repo which then get indexed on each device for structured data, rather than replicating structured data directly. (i.e. imagine a contacts database where each contact is in the repo as a separate JSON doc or similar). Java only for now, thanks to the amount of libs it needs to integrate, and that it hasn't reached proof of concept yet.