Fobs are a far more secure system than keys. if someone losses their key, you just cancel the fob. you can find in an instant who a fob belongs to, who is accessing the building and when ect. The building can be locked remotely, or put on a timer so that the doors automatically lock at a certain time. If someone requires access to, for example, clean the building, they would not require a fob. A EQ or RS pres could open up the building app and unlock the door remotely to let them in. The key is to only allow a select few to have this ability, perhaps three people in a ward. If a building has more than one ward, then just one person per ward. add to this security cameras that can be viewed remotely.
The phone does not act as a fob, but you can open up the security app to deactivate the door. Fobs are fobulous.