Originally Posted by Fox Mulder
Generally speaking, most of the apps touted as battery-savers will actually do the opposite. You're better off just using the available utilities already in Android, and changing settings to minimize battery use (turn down display brightness and reduce timeout period, turn off unneeded radios, disabling background data for apps, etc).
I for one have used JD on all my phones ever since I've been in the smart phone game and I can say that JD is one that actually does work. After doing many many tests, JD has proven that it does save battery. The numbers don't lie. So now I CAN'T NOT use it. I turn it off and my battery just plummets to the ground. If it's set up right, it WILL save you battery though that's a fact. Certain features in the app that I feel are not needed like the auto brightness and settings for nighttime and busy times are ones that will actually eat up your battery. The app will show up in your battery usage when otherwise it doesn't. SO, as long as the app is set up correctly it will save you battery usage.
Just wanted to share my thoughts. Not trying to disregard anyone's opinions on the matter.