Did you ever felt, that one Charger/USB cable set charges your device really fast and the other not? Now, you can prove this with Ampere.
When you turn on the power of the charger charging your phone Ampere informs you that the amount of current charging mAH is being received and information from the battery. Ampere charging current can prevent you from using bad charger. It also informs that the number of mAH charge current mobile phones take when connecting with a USB cable or chargers (AC / Wireless).