face time app disappeared

On the device, open Settings, General, and then About. If the model number has AB, AE, or possibly AH just before the slash, FaceTime will only be there if the installed SIM card supplies it; only ones for some Middle Eastern carriers do, and none of them are in Saudi Arabia or the United Arab Emirates. Otherwise, check the device’s restrictions.

(144116)

could you have moved it into a folder by mistake? Can you find it using Spotlight search by swiping from the middle of the screen down ?

Might it be restricted?

Settings->General->Restrictions->Facetime, make sure its turned on.