Eccco - Record a listen short audios, like Twitter but with voice.
Highlight - "Highlight" physical books through conductive pages 📖✨
Email Comments - Add Google Docs like comments to Gmail
Buglife - Seriously awesome bug reporting for iOS apps
LINER - LINER AI Copilot is currently powered by ChatGPT/GPT-4, Google Search Engine, and information from high-quality highlights of an enormous number of users from all around the world.
SideComments.js - add Medium like comments to your site