The Google definition: zipalign is an archive alignment tool that provides important optimization to Android application (.apk) files. The purpose is to ensure that all uncompressed data starts with a particular alignment relative to the start of the file. Specifically, it causes all uncompressed data within the .apk, such as images or raw files, to be aligned on 4
‐byte boundaries. The benefit is a reduction in the amount of RAM consumed when running the application.
You use the script to zipalign apks using adb by first rebooting into recovery, then mounting /system and /data. Then enter the following code in adb:
adb shell mount -o remount,rw /dev/block/mtdblock4 /system /system/xbin/zipalign_apks