BolusEngine
A personal health app that helps calculate insulin doses for meals and blood glucose corrections, built to make daily carb counting faster and more consistent.
- Role: Personal Project — Design & Development
- Year: 2026
- Technologies:
Project Links
Project Overview
BolusEngine is a personal-use app built to make daily insulin dosing calculations faster and more consistent. It combines a searchable food library, a meal-dose calculator, and an optional blood glucose correction calculator into a single tool, with results logged automatically so previous doses are easy to review.
- Built-in food library with 40+ common items and their carb counts
- Custom food entries that save and persist between sessions
- Combined meal + correction dose calculation in one step
- Deployed as both a native app (Expo) and a standalone web app
The Problem
- Manually calculating carb totals and insulin doses at every meal is repetitive and time-consuming
- Mental maths under time pressure (e.g. before eating) increases the risk of small errors
- No easy way to track a history of doses without a paper log or spreadsheet
- Existing apps often don't support combining a meal dose and a correction dose in one calculation
The Solution
- A searchable, editable food library removes the need to memorise or look up carb values
- Automatic dose calculation from a saved insulin-to-carb ratio, with rounding to 0.5 or 1.0 unit steps
- An optional correction-dose calculator with built-in validation ranges and a high-dose warning
- A running history log so every calculated dose is recorded automatically
- Personal settings save automatically, so the app is ready to use immediately on return visits