Greenified is based off an old web service I use to run that would turn webpages to black and white on the fly. For your computer/device screen to show a bright pixel, such as White, it takes significantly more power than a darker pixel. On mobile devices, the biggest battery killer is the display.
Get the latest .apk setup package of Greenified 1.1 for free and have a look at users' reviews on Droid Informer. You will need 1 MB of free disk space to set up the app that is compatible with Android 2.2 and higher. The antivirus report shows that this application is totally safe for usage. Beyondem Inc. is the developer of Greenified which can be found in the Tools category.
Over 100K users downloaded and installed the app and the most recent release was on Aug 15, 2013. The overall user rating of this application is 4.2. The statistics show that Greenified is popular mostly among Samsung and Lenovo users.