I built a Blood Pressure tracker because I was tired of the existing apps requiring cloud accounts, subscriptions, or selling health data to advertisers.
BP Tracker Pro is a "Class I Data Logger" built with Capacitor and Vanilla JS. It runs 100% offline on your device.
Key Features: - Gorgeous panel to visually track your blood pressure readings - Zero Cloud Sync: Data lives in a local JSON store (encrypted at rest by Android OS). You can bacjup - PDF Reports: Generates clinical reports for doctors using jsPDF (client-side). - Morning Surge Detection: Analyzes AM vs PM readings to flag stroke risks. - Family Mode: Track multiple profiles (e.g., aging parents) from one dashboard.
Tech Stack: - Vanilla JS + Vite (No React/Vue overhead) - Capacitor v8 (Bridge to Native) - Chart.js for trends
https://play.google.com/store/apps/details?id=com.bloodpress...
1derfool•1h ago
The hardest technical decision was not using a backend. I’m using the Android FileSystem API to store everything in a local encrypted JSON blob. It makes cross-device sync harder (I added a manual xml export to ensure you can save data for yourself and family), but it guarantees that if my server goes down (or I get hit by a bus), the app keeps working forever. I also stuck to Vanilla JS + Vite instead of React/Flutter to keep the file size less.
I'd love feedback on the PDF report generation—I'm drawing charts to a hidden Canvas and then injecting them into jsPDF. Thoughts?