End-to-end encryption and privacy controls.
Message and call for free* around the world.
Group conversations made simple.
Say it with stickers, voice, GIFs and more.
Reach your customers from anywhere.
https://123dok.co/document/yng6oeek-ㆍ고장-기능-관계도를-이용한-기능-무기체계의-동시조달수리부속-최적화.html