LED rings R click is a simple board that has an array of 32 LEDs driven by four 8-bit serial-in, parallel-out shift registers. The classic shift register lets you drive many LEDs with just a few pins from your microcontroller.
LED rings probably originate from ring flashes used in fashion photography to make models look like angels, with soft shadows and sparkling eyes. Someone just took the ring part and removed the camera, and now makers are having all sorts of fun with it.
As any array of LEDs, LED rings can also be employed to give visual feedback. The circular shape means you can turn into a clock, or as a loading progress wheel (like the one you see when you turn on an iPhone or MacBook).
The Libstock example has some patterns you can explore. If you want to connect LEDs with your MCU through shift registers on your own, feel free to copy the schematic we supplied on the docs page. If you want to save some time and space and get a LED ring click right away, you can do so from the product page.