Hi,
here is a simple bug fix in order to support RTL languages:
in signwriter.module add the method
function utf8_strrev($str){
preg_match_all('/./us', $str, $ar);
return join('',array_reverse($ar[0]));
}

then in
function signwriter_theme_text(...)
add the code:
if (mb_detect_encoding($text) === 'UTF-8' ) {
$text = utf8_strrev($text);
}

This should flip any utf-8 and would fix the problem of rtl language displayed backwords...

This has a bug where strings that contain utf-8 that is not an rtl language or string that are mixed will be displayed fliped
possible solutions:
1. add a config option to enable/disable the utf8_strrev method,
so that sites owner that wants rtl will be able to enable this feature

2. change the call "mb_detect_encoding($text) === 'UTF-8'" to a more sophisticate function that scans the string and convert only sub-str that are in an rtl language --- this is the correct solution but a little more difficult to implement

Otherwise works grate,
Thanks
Elia