Automatically sync folder contents in the background

Do you remember some of the filenames?

Try to enable Spotlight to search documents, and use it to find the file you misplaced. You should be able to find it if it’s still inside your Documents folder.

Using Terminal

My last attempt would be using Terminal to list all the files containing your files content keywords. Run Terminal and enter command below (replace your file content with some of the unique keywords in your lost documents:

grep -R 'your file content' *

It should display all the file it can find on your User folder. If it still can’t find the files, they’re most likely gone forever.

BitTorrent Sync does exactly what you want. It syncs over LAN by creating a "secret code" between the synced folders. You have the option to view your files on an iOS device through their free app. It's free and supports multiple platforms.

This is quoted from their website:

• Sync and Share - Sync unlimited files between your own devices, or share a folder with friends and family to automatically sync anything.

• Private and Secure - File transfers are encrypted. Your information is never stored on a server in the cloud and your data is protected by private keys.

• Bigger is Better - BitTorrent Sync is specifically designed to handle large files, so feel free to sync original, high quality, uncompressed files.

I have been using it for couple months now. It's pretty much set it up and forget it.