Today only, until 4 pm ET (or 100% claimed), Sunvalleytek via Amazon offers Prime members the RAVPower 17-watt 2-Port USB Travel Wall Charger for $8.79 with free shipping. (Non-members can get free shipping with orders of $35 or more; otherwise, shipping adds $6.98.) That's the lowest total price we could find for a similar device by $17. It features two ports, one for Apple devices and the second for most others.