Along with the two new Kindle e-readers and four Fire HD tablets Amazon announced on Sept. 17, the e-commerce company, looking to get a foothold in the hardware market, also launched Sangria, the fourth update to its Fire OS running on its tablets and the widely panned Amazon Fire Phone.

Unfortunately, not much of the world took notice as technology enthusiasts were more interested in iOS 8, which was also released on the same day. Unlike Samsung, which chose to introduce its own Galaxy Note 4 and Galaxy Note Edge ahead of the hotly anticipated release of the iPhone 6 and iPhone 6 Plus, Amazon decided that Sangria had to go head to head with iOS 8.

Fire OS is a customized version of Google's Android 4.4, although users of Amazon devices say there is not much of KitKat evident in the platform's design. The fourth version of Fire OS is more of a feature update than an all-out makeover, with Amazon introducing new features that will make its new Fire HD 6, Fire HD 7, Fire HDX 8.9 and Fire HD Kids Edition more functional than its older devices. New features worth noting include support for multiple profiles, better battery life and support for Firefly.

Multiple profiles is a feature adopted from Android, which lets several users have separate accounts on a single device. This makes it possible for different family members to share one tablet while having individual apps, carousels and libraries. However, families will still be able to share their content with other members through Sangria's Family Library, which works across profiles and across Amazon devices. Multiple profiles also allows single users to create separate accounts for work and play.

Amazon also introduced Smart Suspend, a feature that will save battery life by automatically turning off wireless connectivity after a certain period of unuse. This, Amazon says, will help the user save up to 25 percent more battery life on the Amazon device. Along with Smart Suspend is ASAP or Advanced Streaming and Prediction, a feature that Amazon first introduced on its Fire TV that tries to predict what movies and TV shows the user will watch next and streams them ahead of time in the background. The company says it is bringing ASAP to Sangria "by popular demand."

Also available on Fire OS 4 is Firefly, which was first debuted on the Fire Phone. Firefly lets users take pictures of products and scan bar codes, URLs and phone numbers and upload them to Amazon to help them look for products faster.

Sangria will be available as an over-the-air update for all Fire HDX tablets on an unspecified date. The OS comes pre-loaded on all new devices announced on Sept. 17.