Lepow Official via Amazon offers Prime members the Lepow Moonstone 3,000mAh External Battery Pack in Apple Green, model no. L-MS3000-AppleGreen-US-01, for $18.99. Coupon code "2JDA3K2Y" cuts it to $9.99. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $5.40.) With free shipping, that's $30 off list the lowest total price we could find. It features two USB ports and is compatible with most smartphones and tablets.