Based on Reddit discussions, there is clear interest and demand for privacy-focused health tracking apps among users who track weight, blood pressure, and other health metrics. Many users express frustration with existing apps that collect and sell their data or share it with third parties. The key appreciated features are:

Apps that store data locally on the device without requiring account creation.

Transparent and straightforward privacy policies that guarantee no data access or selling.

Offer of meaningful insights without compromising user privacy.

Willingness by some users to pay a premium for such privacy-respecting services.

Users often recommend apps that ensure data remains private, such as those that do not upload data to cloud servers or share with advertisers or insurers. Some are even developing their own apps or seeking open-source solutions for better control over personal health data.

In summary, a health tracking app focusing on weight and blood pressure monitoring that emphasizes no data selling, no third-party sharing, and strong local data privacy is likely to find interest on Reddit and among privacy-conscious consumers. The market has demand for trustworthy, privacy respecting health apps, and users are vocal about their needs for transparency and control over their health data