XTextureExtractor extracts the textures for the HSI, ND, EICAS, and CDU displays, and renders them in separate windows that you can place anywhere within X-Plane, on external unused monitors, and on separate computers via a network protocol. The Android app allows you to view the panels on multiple phones or tablets, in either landscape or portait mode, and you can cycle through the available panels by tapping on them. There is also a java-client included in the download archive, which can run on most Windows, Linux, OSX, and Raspberry Pi hardware.
Most X-Plane 11 aircraft only allow you to view these displays within the virtual cockpit. These displays can also be quite small and hard to read, and it is ideal to have them viewable directly from their own display. Almost no aircraft in X-Plane support the ability to pop out any of these displays. There are apps such as XHSI or ZHSI, but these reimplement the entire aircraft display system from scratch, and require the developer to constantly match the latest aircraft. XTextureExtractor simply grabs the textures directly from the aircraft via the GPU, so the external displays are a pixel-perfect copy.
Almost every aircraft in X-Plane with digital displays (not steam gauges) is supported, such as: the standard X-Plane 737 and 747, the Zibo 738 and Ultimate 739, Flight Factor 757, 767, and 777, Felis Tu-154, SSG 748, Magknight 787, CRJ-200, and many more! It is also easy to add new aircraft by creating a new .tex file and specifying the texture coordinates.
Main download: https://forums.x-plane.org/index.php?/files/file/42612-xtextureextractor/
Android app: https://play.google.com/store/apps/details?id=net.waynepiekarski.xtextureextractor&hl=en
GPLv3 source code: https://github.com/waynepiekarski/XTextureExtractor