Noom Walk is android pedometer app which counts your steps without killing your battery. Its a nice little app which runs in background and counts our daily steps walked. Its not perfect as it shows 10% to 20% more steps every time I have tested it. But the as it does by hardly using any battery life is a big plus point. Also it has a social factor by which you can tag your friends and compare your progress with them. The only thing missing is how to control your social contact whom to allow seeing it as it doesnt have that feature either you show it to all or go in private mode and dont show that to any one.