Samsung today released its Power Sharing cable for a selected few Galaxy devices, which will allow them to charge other devices provided it has a microUSB port.
This $20 cable will only work with a selected few Galaxy devices including the Galaxy S5, the Galaxy Note 3, Galaxy Avant, Galaxy Tab S 10.5 and 8.4, and the Galaxy Alpha.
To use this cable, you will also have to download the accompanying Power Sharing app from the Play Store, which will allow you to select the amount of power you want to share with the other device. While this cable will not really be useful in charging any of your other devices to 100%, it will still provide them with enough juice to last a few more hours.
As of now, the Power Sharing cable from Samsung is only available in the United States for $19.99 in black and white.