This is a pre-compiled version of ExtPlane from https://github.com/vranki/ExtPlane.git It is only available for Windows, but can be built for Linux and OSX if needed.
This pre-compiled version is needed to support XPlaneCDU, which requires the latest bug fixes from the master branch.
You should extract the ZIP file and copy ExtPlane-Master-MinGW-23Jan2018 into your X-Plane 11 Resources/plugins directory. This directory should contain various DLL and XPL files, and no extra sub-directories.
XPlaneCDU is available from Google Play for Android devices from: https://play.google.com/store/apps/details?id=net.waynepiekarski.xplanecdu
The source code for XPlaneCDU is available from: https://github.com/waynepiekarski/XPlaneCDU
Eventually when ExtPlane does a new v2 release with binary builds, this repo will no longer be needed.