This addon was made by d6d, and according to him, he was trying players who were seeking something extravagant. Nevertheless, other players use it properly without destroying the server’s ecosystem and balance.
However, in Minecraft PE, some dishonest users apply it quickly to find precious ores and other rare materials, like diamonds. Doctors make use of it when there is something they want to see inside the body. X-rays are typically used in medicine to see through the human body. Download XRay texture pack for Minecraft PE: look through blocks and other materials in search of rare ores without problems.