Let me start by saying that I am a big fan of tangible user interface (TUI) and natural user interface (NUI). A ring interface is referred to a smart ring wearable device that is supposed to be at the intersection of TUI and NUI. Unfortunately, none of the existing products is appealing in my own opinion.
I am not sure if this one was the first, but it surely created a buzz. The Ring, which claims to be a shortcut of everything, was successfully funded on Kickstarter. However, the product itself appeared to be very disappointed. An unhappy user created a video to thoroughly review the product, which forced the ceo came out to make another video to clarify. The whole thing feels like a very good marketing story.
Fin, similarly, proposes to use the ring to control "a lot of things" without the need of looking at the device, such as changing the volume of your MP3 player, taking photo from your camera, or pausing video with a head mounted display. I will give them credit of making a better video than Ring, but the use cases are still not convincing. I will explain why in a bit.
Another very similar but a little advanced product, MOTA SmartRing, adds a screen on top of it. The screen certainly makes it more appealing than others. It allows the user to do a quick glance at it. I suppose the idea is to see how many messages you are having so you know if you need to pull the phone from your pocket and look at it. They call it "disconnect to connect".
Nod is one ambitious product that appear to embed many sensors together. In addition, it supports Bluetooth scatternet, so it can maintain multiple connections with different device at the same time. Compared to its rivals, Nod does the best job in its API. Their API does not only support different types of device, but also works well with Unity. It is actually a brilliant move because it really opens the door of creativity. However, to some degree, I feel that they try to achieve too much.
Yes, if you must ask.
Fujitsu is apparently one of them. But it is unclear that anything will come out soon.
Some rings that try to do much simpler things and I think that probably can attract more users.
A ring called ThumbTrack that tries to put a mouse on your finger. It is not a totally bad idea depending on the scenario, unfortunately they haven't built one yet.
A few rings have built-in NFC and are designed to help you with something very simple. For example, SESAME RING, which helps you to enter the subway entrance. TiMER, NFC RING (can't they find a better name?), and GalaRing (website in Chinese), which are all designed to collaborate with your smart phone, such as screen unlock, app launch, file sharing, and so on.
Finally, a unique "smart" ring, Ringly that serves just the notification purpose (when an important message comes in, it viberates to tell you to look at the phone), but it focuses on the fashion and luxury side. Each ring costs $195. It is not cheap; however, I personaly feel that it is much more appealing than those real "smart" ring. And I am a man, for the record. The ring looks beautiful and elegant. The problem it tries to solve is clear and simple.
To me, there are a few problems of those smart rings:
Those smart rings are trying too hard. They tend to achieve too much from a very small device, i.e. controlling everything. It significantly increases the complexity of using such a device, as well as the engineering of the hardware and software. The creators of those rings all seem to hold a thought that they are building a brand new device, which can rule everything, as opposed to just introducing an add-on device.
Why? Because a ring IS just a companion NOT a replacement. That's also why I feel the rings that are doing less likely will earn more users.
I could be wrong, because people used to think a cellphone is nice to have not must have. All the features those rings try to apply can be done with a phone. The only scenario a ring comes really handy is that when both of your hands are tied up, while you desperately need to send a command to your device.
A scenario I can think of is that I am cooking with my hands full, but I want to view the next page of the recipe from my tablet. It is still a horrible use case. I would prefer to use voice command, or in-air hand gesture, which can be captured by the tablet camera.
Some use cases I have seen, including text-entry (OMG!), adjust volume, flip to next page, and change to next song. The list can go on and on. They all can be done using other ways more effectively.
In interface design, we all know that it is very important to minimize cognitive load to maximize usability. A ring that rules everything clearly doubles, oh wait, triples, hmm, infinitely increases the meantal load of a user. Just think about gesture. How many gestures can you memorize? Not to mention when asking you which gesture is use on which device paired with your ring.
We are all just dreaming better future. I agree that building those rings is a way of exploring a better future. I truly believe that there are better alternatives to the smart rings. Smartwatch with Nature Language Processing might work better. Depending on the concrete use case, a gesture can be applied directly in the air without wearing anything. A ring is likely a transition product and we are waiting for the next real smart thing.
It is indeed very exciting to see such a product line has emerged. Unfortunately the value proposition of them are low (IMO). Therefore, I feel that they are hard to take off. On the other hand, some other rings that try to do less might have a better chance to earn more users. Let's hope NLP advance faster so we can have smarter robots to talk to and execute our commands. I wonder if that day really comes, will it really be a better future?