Monitor your location and 
auto lock or unlock your Android devices when needed!
This works in a way that, as long as you remain within an area that you have setup as trusted, the device will 
remain unlocked. Once go out of 
safe/trusted place, device will lock itself 
automatically!
To do so,
Navigate to 
Settings --> 
Security --> 
Smart Lock --> 
Trusted Places**Also have Trusted Voice, Devices, Face and On-body detections - that works in a similar way!
Note:
If Trusted Places isn't listed, have to wait until Google Play Services update is pushed to your device. 
Works from Androidv 5.0 (Lollipop)
*