playSMS plugin's files and folders installed under directory web/plugins 
and categorized into 4 different categories, they are:
- tools
- feature
- gateway
- themes
- language


Tools
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Here installed plugins with no specific SMS related features but used by playSMS.


Feature
-------
Here installed plugins which contains specific SMS related features and directly handle
incoming or outgoing SMSes.


Gateway
-------
Here installed plugins which has ability to actually send and/or receive SMS, and directly
connected to SMS gateway applications or services.


Themes
------
Here installed playSMS's themes.


Language
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Here installed language database based on gettext