Here is an alternative solution i made here that take virtually no battery, and root
Originally Posted by Ubelsteiner
Wear Unlock will do it, but I experienced some battery drain (on the phone) that I believe was related to it (since it went away when i uninstalled it).
Either way, I found the app to not be as helpful as I originally thought, just because of how good the reception between watch and phone is. I have to basically leave my house before it would lock my phone, I was hoping for a solution that would lock my phone if I just stepped outside of the room. Plus, with Wear Aware I get vibrations when the two lose communication anyway, so its not like I'm going to forget it somewhere and wish it was locked anyway.
Here is an alternative solution i made here that take virtually no battery, and root is not needed.