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://studentedu.farafile.ir/file/42472/جزوه-ریاضی-عمومی-1--دکتر-واعظی-(دانشگاه-شهید-رجائی)