Which technology giant will be the first to offer a free smartphone? Amazon.com is making a play. In a previously unreported move, the online retailer and Kindle maker is considering introducing its long-planned smartphone for free to consumers, according to people familiar with Amazon’s effort. There are many unanswered questions about the plan and what strings will be attached for customers. One of them is whether Amazon would require its smartphone owners to pay for services such as Amazon Prime, the company’s loyalty program. But the people familiar with the matter said that Amazon wants the device to be free whether or not people sign up for a new wireless plan at the same time. (Wireless carriers typically discount the price of devices if customers sign up for a one- or two-year wireless contract.)