From GameBrew - a wiki dedicated to Video Game Homebrew.
Have you hit the 300 title limit on your 3DS, and/or want more than 300 titles, but don't want to make an EmuNAND (or 2nd one), or use another SD card? The answer, is 3DSBank!
With this, you can store your
Nintendo 3DS folder into a bank, and select or create another one to use, containing your other titles (and themes, and badges).