Here is the fundamental engineering rule you need to understand:
One evening Mina showed up at Jules' door, cheeks flushed from rain. She held the phone between them, scrolling. "These," she said, tapping a wobbling-tears emoji, "make me feel like your messages have lungs." Jules realized the costume had done more than disguise; it had given shape to a voice that had always existed, waiting for the right instrument. facebook messenger ios emoji apk