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.
http://lono.farafile.ir/file/20556/پاورپوینت-فصل-هفتم-کتاب-تجزیه-و-تحلیل-و-طراحی-سیستمها-(زاهدی)