XtreamResell - https://xtreamresell.com/
ProjectX is addon that provides seemless integration with xtream codes. It uses whmcs at its core. It is designed for the backend xtream codes reseller, not the top tier xtream-codes panel owner. ProjectX will automate tasks such as adding users, credits and automated billing. ProjectX is also not restricted to working with just one panel and can be used on as many panels that you may be subscribed too. ProjectX can also solve Captcha's so even if your Xtreamcodes panel is protected by a Captcha ProjectX will still have all its Functionailty.
Admin Area Features: Create/Suspend/Unsuspend/Terminate Service.
Change Package - Supports Configurable Options.
Client Area Features: Create/Terminate Service.
View Service Details.
For more info: https://xtreamresell.com/wiki/index.php/ProjectX_For_WHMCS
This is the PHP 5.6 version fully decoded via EasytoYou.
This isn't nulled but can be easily done seeing as the full source code is available.
Note: I take no responsibility for the use of this code as I just like to see sources and how things are put together, if you plan on using please support the developer.