The plugin launches executable files at the plugin initialization, i.e. right after Idea start.
A folder, where scripts are located, is "/home/$USER/.idea-post-launch-hooks".
I used this plugin to change default value of /proc/$PID/oom_adj. It was hard to set it in the idea.sh because Idea forks and the actual PID is different.
I wanted to set oom_adj because Idea is a heavy memory consumer and it could relatively safely killed by OOM Killer because of auto save.