Login Approvals will (as Google Two Step Verification) send you an SMS message with a verification code that you must enter, every time you login using an unknown device.
I assume we all have the notification by email when we login using a new device?? Well this takes it one step further.
*Well I do, because I have exchanged messages to people using the Facebook messenger, but even still this is not something to be taken lightly, because we have a wealth of information that we take for granted. What we might consider to be insignificant information about ourselves might be valuable to others or an angle for them to electronically attack us from. Be careful and take the privacy of your online personal information very seriously.