You do not need a separate device or pedometer. This app will count your steps with nothing else needed! You can also view your steps, distance and calories for this week and the previous week to make sure you are challenging yourself! Always on and works with the phone you have! Steps does not waste any additional battery life, so keeping track of your steps, distance and calories burned has never been so easy. Steps is the simplest pedometer and activity tracker out there! Get moving today.