Amazon Kindle Unlimited regularly offers free subscriptions every few months, in order to dive adoption to their reading platform. Today, the company unveiled an early Prime Day deal, where you can get a three month subscription for free. Kindle Unlimited is a monthly subscription that gives members access to more than 4 million digital books, as well as thousands of audiobooks, comics, and magazines. Once you activate your subscription, you can immediately start downloading titles from the Kindle Unlimited catalogue. Kindle Unlimited works with all Kindle devices, as well as on your phone, computer, or tablet through the free Kindle app.