As I understand, the Moto X, Droid Maxx and Maxx Ultra, and ?? maybe mini there is an app already included. For other phones, you can use Tasker. I bought some of these Cobra tags and will try it out.
I'm new to Tasker. I just loaded it on my N5 this last week. I'm still in my learning curve. I can't get Tasker to work yet as far as bypassing my PIN when I am connected to my home wifi. I was hoping that when I am at home connected to my home wifi, my phone will remained unlocked. I have Dynamic Notifications loaded as well and the DN locksreen set, so I don't know if it is interfering with Tasker.
I will see if Tasker will keep my phone unlocked with this bluetooth tag. The only concern is when I go to my car, I'm not sure if my phone will disconnect from the tag, and then try to connect to my car bluetooth. Once disconnected, I'm curious if the tag will beep like I'm separated from my phone.