The Sharing of Isaac is a sharing savegame system for The Binding of Isaac: Rebirth which will allows you to use a single savegame in both PC and 3DS versions of the game! It can also be used as a cloud space where to save your savegames if you don't own a PC or a 3DS version of the game.
Can i setup a private server?
If you have a working development environment and an host with a MySQL database, setting up a private server it's quite easy since the project is COMPLETELY OPEN SOURCE.
Sourcecode is available on this GitHub repository: https://github.com/Rinnegatamante/The-Sharing-Of-Isaac
MasterFeizz for spending hours explaning me how to send a POST request with sockets.
ihaveamac for compiling the client for Mac and Linux.
How to use
DISCLAIMER: The project is currently in BETA phase so first of all i HIGHLY SUGGEST you to take a backup of your savegame (PC version: persistentgamedata1.dat file, N3DS version: gamedata1.dat file).
Register to the service with this page ( http://rinnegatamante.it/TSOI/register.php ) and follow the instructions on screen.