In my searches everything I would find was resource or battery hog intensive. Until along came this Llama app to my attention. I have been running it now for a few days and it has not put a ding on my battery life and when it learns your areas it will automatically do as you set it up to do! I can have my phone now automatically silence itself when I get to work! No more having to do it manually or use a play store widget to silence my phone, which by the way was acting up lately and would not restore volume so I ditched it.
Llama is by far a recommended app for anyone! You can use it to silence your device when you are in a classroom for example and when your not there it automatically restores for you your settings. You can have it set to the loudest settings when your at the nightclub or tavern or even vibrate instead.
I have not yet fully used Llama to the fullest potential but I look forward to exploring it more!
Google play store - Llama
Let me also add it is a free app but they do accept donations. Another nice thing is that this app does not rely on GPS but actually uses the towers to help tell where it is and based on your trekking it to learn a location it has been spot on for me.
As far as battery use, it doesn't even show up on my battery stats and I have not seen any increased drain because of it and if I had to venture I would say battery seems better. But I am sure that is all psychological.
A new must have App for me!