We having great sales on new iPhone 6S and iPhone 6S Plus. However, too many users bring them back to ask for solution because the AirPlay icon which can be so useful stream music and videp to the AirPort Express and Apple TV) is missing and hidden somehow from your iPhone.
The tip to fix this problem is so simple and funny, but it works actually.
Go to Settings > General > International > Language > then Switch to another language > The iPhone 6S must restart it-self after the change > AirPlay Icon should be shown after reboot.
And then you can switch over to your preferred language.