Arabic support on non-rooted Nook Simple Touch
Nook simple touch is the second generation of e-readers made by B&N , although it's released in 2011 ,it's based on Android 2.1 (released in 2009 !) , and hence its native support for Arabic ebooks is very poor, combined with fact you can't change system fonts , all you will see is bunch of ? squares here is a sample of Arabic Epub book on NST:

so , is there any way to overcome this problem ?
Rooting is the easy and the best way , once the device is rooted , you can replace certain files
with patched ones +replacing DroidSansFallback.ttf with any arabic font ( I use DroidSansNaskh (don't forget to rename it ) in /system/fonts to have proper support of Arabic, once done you will see Arabic texts in most apps (ES file explorer, EzpdfReader , etc)

For Arabic eups reading I highly recommend using moon reader+ pro 1.6 or any version that supports RTL (Right to left texts) .

and even with this method bn stock reader won't display Arabic texts properly as its engine doesn't understand/support RTL .
so , all mentioned above is for rooted devices, what about poor non-rooted NST users?
well, here what I did
[css font hack]
first we are gonna use sigil as epub creator tool ...
create a new epub file
edit the html source and add the following
@font-face {
font-family: "Droid Sans Naskh"
font-weight: normal;
font-style: normal;
src: url('res:///sdcard/fonts/DroidSansNaskh.ttf');
}
4.change the source of ttf file accoring to the location of the font you want to use.

now the hard part,
by default ,as you can see above, NST reader displays the Arbic words reversed and with un-connected letters, so we need to modify the text in a form NST can display properly
they are different way to do it but the most accurate way is to use php class called Ar-PHP
to use the script , I will assume you use linux ,
install php on your system
download Ar-PHP class[ all credit goes to Khaled Alshamaa ]
extract the file to any folder you like
create 1.php file in the I18N folder and paste the follwoing code
<?php
include 'Arabic.php';
$lines = @file("1.txt");
$obj = new I18N_Arabic('Glyphs');
foreach($lines as $line ){
$text = $obj->utf8Glyphs($line);
echo "$text \n" ;
}
?>
paste your arabic text in a txt file named 1.txt
in your terminal cd to the I18N directory
cd /home/live/Downloads/Arabic-3.6.0/I18N
execute the follwoing command
php a.php >2.txt
the converted arabic text will be saved in 2.txt
open the file and copy the uncomprehensible back to sigil , save your work ..
this is how the file will be displayed using NST reader .

the result is satisfying =) , thanx to the php-Ar class , diacritics handled and displayed properly on the NST., but alef-lam combinations needs some work from the developer.
you can download all the files needed from this
link
If you have a question , or want a clarification ,leave a comment