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.
자바스크립트 예제: 특정 주파수의 소리 재생 + 음악 평균율 주파수 테이블 http://yoonbumtae.com/?p=1677