I have looked into this idea of geo-fencing , and it does have some serious security issues that need to be thought through. At first I loved the idea of having my front door unlock, porch and living room lights automatically come on as soon as my phone connected to my home WiFi as we puled into the drive. Think about this though, you are always on your home network when you are home.
Let me put forth this scenario,it's late in the evening you are out back in the hot tub with the significant other having some wine, listening to music and somebody can just walk into your house because you're phone is connected to your network so the front door is unlocked. In another case you may have your phone PW protected, to get past lock screen to open apps,but it still connects automatically. You forget your phone at the pub, somebody gets/knows your address and now has the ability to just walk into your home, right past any and all security you may have.
It may sound great, but has way too many security risks involved. I can deal with having to unlock my phone and tap an app to turn on my lights and open the door. I have a motion detector linked in on the front porch anyways that turns on the lights as I pull in and I can unlock the door from the car if I have my hands full. Nobody in our house carries house keys anymore anyways since we put in the Schlage touchscreen locks.