Hands-on tests and comparisons of smart rings and other wearables, using reference devices and long-term data to check how accurate their heart rate, HRV and sleep metrics are. Also covers the research and personal experience behind wearable use, such as orthosomnia.

A personal newsletter documenting one author's self-experiments with wearable data, including HRV tracking, heat running and the development of their own recovery app, Nunc. It reads as a first-person lab notebook that questions the value of commercial recovery metrics.

BTTR Reviews is an Australian tech review newsletter covering consumer gadgets such as smart home cameras, doorbells, and AI glasses. Readers get hands-on reviews and launch coverage with practical notes on battery life, privacy, subscriptions and local pricing.

A Spanish-language newsletter that presents business case studies, MBA-style, drawn from current digital business news such as OpenAI's move into advertising and Oura's strategy. Each case is released in two parts, a statement of the problem followed by a resolution analysing the company's options.