I've just launched a new Chrome extension named Blink, which is inspired by a comment made by TheRealHB on HN. It suggests using a blinking LED to combat ADHD and maintain focus:
Blink replicates this technique by introducing a subtle, pulsating rhythm to your Chrome toolbar. The pulse begins at a quicker pace, similar to a rapid heartbeat, and then gradually slows to a calm, steady tempo. This visual cue is designed to be noticed in your peripheral vision, gently encouraging your brain to sync with its pace, potentially aiding in concentration.