[Lydovig]

I was able to establish a normal work with firmware 5.0.0

Spoiler:

#!/bin/sh
EXTENSION=/mnt/us/extensions/skipstone
#init_orientation=`/usr/bin/lipc-get-prop com.lab126.winmgr orientationLock`
#/usr/bin/lipc-set-prop com.lab126.winmgr orientationLock R
cd ${EXTENSION}/bin
export PATH=${EXTENSION}/bin:$PATH
#export GTK_IM_MODULE=kindle
./skipstone
#/usr/bin/lipc-set-prop com.lab126.winmgr orientationLock ${init_orientation}

It turns out that simple. Everything works fine. Run the keyboard button which is located near the address bar.