Force library refresh on Nook Simple Touch

If you have rooted a Nook Simple Touch e.g. using http://forum.xda-developers.com/showthread.php?t=1343143, you may want to run some scripts to download some books directly onto your device. The problem is that these books you saved to /media or /sdcard only show up in the library after you reboot the Nook.

To force a library refresh, create a script containing the line

busybox killall vold

of course you need to have busybox installed through Google Play and you have to run this script with root permissions.