Samsung was one of the first companies to launch what we may consider modern smartwatches, the Galaxy Gear was introduced in September 2013, its successor was announced 5 months later called simply Gear 2 and a plastic version of it named Gear 2 Neo along with another one with a new form factor called Gear Fit and switching the operating system from Android to Tizen in all of the devices. A few months later, when Google unveiled its operating system for wearable devices, Samsung also announced a version of the Galaxy Gear lineup that would run this new operating system and would be known as Gear Live. Finally, in November 2014, the company introduced the Gear S, which is the best smartwatch they've released and still is one of the best offerings for this kind of devices, featuring a 2-inch curved screen and 3G connectivity, it's basically a very small version of a smartphone.
Since then, we've only heard some rumors about a new smartwatch that features a round screen and new ways to control it with the bezel surrounding it. First it was known as Samsung Orbis and all we got were some sketches or renders of how it might end up looking. More recent rumors suggest that the name will be Samsung Gear A, suggesting that it will use premium materials like in their Galaxy A smartphones. A lot of details are still missing like the operating system that it will use, though it will probably be based on Tizen, but thanks to an SDK that was released, we know not only that it will work on rounded screens but we also got to know the interface a little better as well as the way it will interact with the ring surrounding the display.
Now, a tweet from the Samsung Exynos account seems to confirm some of the previous rumors, the image shows a rounded-screen interface for the heart rate monitor function and it is simple and clean like in the pictures of the SDK, so it strongly suggests that this is about the Gear A, and being written from that account it hints that the processor that will equip this smartwatch will be made by Samsung just like in most of their other smartwatches. The new device will probably be announced along the Galaxy Note 5 sometime in the fall.