This is the SMS4 software package.  It can (as far as I can tell) backup and restore save files for DS and 3DS games (not counting WarioWare DIY).

There are two important files included with this package (though all the others need to stay where they are):
 - NEO 3DS&NDS SMS2 Backup Master V1.26.exe - This can backup any DS or 3DS game without an IR port. (No HeartGold/SoulSilver or Black/White).  Use the other file for that.  It will not install a driver, so if it doesn't work, you may need to install the other file first.
 - Neo2 Pro Manager 1.11 Setup.exe - an installer that once installed, can backup any DS game, but not any 3DS game.  It will install a driver.  If the driver install fails, try again with the SMS4 plugged into your computer.  If you find a later version on the internet, then it might not be able to backup games with an IR port.