KetoBM

Overview

KetoBM is a metabolic health system — an FDA-cleared Bluetooth meter paired with a companion mobile app. The app connects to the meter over Bluetooth, automatically syncs blood glucose and ketone readings with no manual entry, and shows results in real time.

Beyond capture, it turns readings into insight: a logbook of every measurement, trend charts across daily, weekly, and monthly ranges, and statistics like averages and ranges. It’s built for people on ketogenic and low-carb diets, and anyone tracking their metabolic state and fasting over time.

My Role

I built the companion mobile app that pairs with the KetoBM meter.

• Implemented Bluetooth pairing and the sync flow (react-native-ble-plx) that pulls glucose and ketone readings from the device automatically.
• Built real-time reading capture so results appear on the phone the moment the device records them, backed by local-first storage (Expo SQLite) with Supabase as the sync layer, run locally in Docker during development against separate preview/production projects.
• Developed the logbook, trend charts, and statistics that make readings understandable at a glance.
• Prototyped the meter’s BLE behavior on a breadboard — with two buttons to trigger a ketone reading and a glucose reading — and wrote C++ firmware to emulate its GATT profile, so the app’s pairing and sync flow could be tested against real Bluetooth traffic without needing a physical meter on hand.

Key Challenges

Testing BLE without the real device. To iterate on pairing and sync without depending on the physical meter, I wired up a breadboard rig — with separate buttons to trigger a ketone reading and a glucose reading — and wrote C++ code to emulate the meter’s BLE GATT profile, letting me exercise the app’s Bluetooth flow against real radio traffic on demand.

Reliable Bluetooth pairing and sync. Talking to a physical medical device over BLE means handling connection drops, retries, and out-of-order data so a reading is never lost or duplicated.

Real-time reading capture. Results have to reach the phone the instant the meter records them, which puts a premium on a responsive, correct data path from device to UI.

Trends and statistics at a glance. Raw readings only help if they’re legible over time — the charts and stats had to make daily, weekly, and monthly patterns clear without overwhelming the user.

Outcome

Shipped to the App Store and Google Play as the companion app for the KetoBM meter.