The new version of Boot9strap 1.3 has been released. This new update makes users to use NTRboot more easily. Here are Boot9strap 1.3 changelog: Sources from github
■ Removed some unnecessary padding to make B9S FIRMs smaller (they now size about 30 KiB, and thus can support NTRboot targets with smaller flashes).
■ Updated the filesystem library used by the stage 2 loader.
■ Added additional delay following ntrboot to allow for more time to hold a button-combination for the loaded boot.firm.
If you have Boot9Strap installed and you are currently running the 1.2 version, you can folllow the video to update Boot9Strap to the latest version 1.3. If you did not have B9S and are ready to install it, it is easy to hack your 3DS with getting a R4i gold 3ds rts