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://knowledge.farafile.ir/file/36619/پاورپوینت-(اسلاید)-فضاهای-نيمه-باز-و-مثبت-منفی-در-معماری