[simplerman]

I tried to build this for my MVP which was also CRM. I stopped for other reasons, but this is how I was doing:

1. Store data locally in SQLite.

2. Export from DB to JSON string.

3. Encrypt JSON with in memory password.

4. Save encrypted string on backend server running Laravel and MySQL.

Basically, I provided backend only for sync functionality. And I liked that data was encrypted on client, so I had less liability.