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://pdf-doc.ir/product/16284/دانلود-پاورپوینت-سری-فوریه-سیستم-های-زمان-پیوسته-و-زمان-گسسته