The plugin is intended to switch text layout in the input fileds (all text, selection or current word) (E.g. (EN->RU): Ghbdtn? rfr ltkf& - Привет, как дела?) or displaying "decoded" text from readonly fields (in logs of RTF, History++, IEView) using a popup with ability to copy result to clipboard. As of version 0.0.1.0 the ability to change register of symbols was added.
Keyboards layouts are arbitrary, their list is taken from system layouts. For text conversion configurational strings are used, which beginning from version 0.0.1.0 are generated by the plugin itself(!). The ability to edit this strings is temporary left in case of incorrect strings generation for layouts which weren't tested by author.
There is ability to define hotkeys for all above functions.
Questions and requests also bugreports on russian forum: http://lemnews.com/forum/viewtopic.php?t=1493

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ChangeLog:

0.0.1.4
* Fixed error in hotkeys setup GUI
* Fixed configurations strings generation for layouts with zero symbol
* Added ability to change Caps Lock state on lettercase inversion (optional)
* Removed the "Layout of text is the current layout" option. Now combined method is used for layout detection of converted text. 
* Added a check for IM client.
* Small bugfixes.

0.0.1.2
* Enhanced abilities of hotkeys configuration
* Minor bugfixes
* Thanks to induction for icons

0.0.1.1
* Added Updater support
* Fixed crash when making conversion in History++ window
* Minor bugfixes

0.0.1.0
* The plugin is uploaded to FL for the first time.
* Compiled in two versions: ANSI and Unicode
* Generated UUID: {c5ef53a8-80d4-4ce9-b341-ec90d3ec9156} (UNICODE)
   		   {87af74ba-035c-4d0d-b68d-d0d6ae1ebfcd} (ANSI)
* Memory leaks were fixed
* Generation of configurational strings is done by plugin without using predefined strings.
* Only those configurational strings are kept in the database which differentiate from default strings (generated by plugin). Names of parametrs are changed to reflect full HKL value for layout.
* Added ability to change the register of text.
* Added ability to use alternative hotkey for text conversion.
* "Current word" mode is set for each hotkey, not globally.
* Added ability of two-way text conversion if system has 2 layouts. (E.g. (EN<->RU): Jgthfwbjyyfz cbcntvf Дштгч ckj;yf lkz hzljds[ гыук-jd - Операционная система Linux сложна для рядовых user-ов)
* Added ability to play sound on conversion (Options - Customize - Sounds)
* Added ability of "decoding" text for History++ log without entering the pseudo-edit mode of message (with ability to select several messages)
* Displaying of "decoded" text for readonly fields in popups (if a popup plugin is installed and enabled) or in MessageBox (in the opposite case). Popups settings are at Options - PopUps - ChangeKeyboardLayout
* Thanks to induction for default icons for popups
* Added ability to change popups icons
* A lot of code optimizations and tweaks.