Battery Saver DX+Switch Widget
I tried JD ultimate for a long time and never got much from it.
I also tried Greenpower.
The above comments are spot on. You want a fine balance between making it actual work to use the danged thing and yet still be effective.
This app is intuitive, you know what switches are on and which are off. Easy to flip if you need.
And what kicks my behind is my battery lasts, quite literally, for days now.