Delta is a calorie-deficit tracker for people who already know what to eat — they just want to see if they're actually doing it. Every day collapses to a single number: how much of a deficit you ran, based on what you ate (logged in Apple Health) minus what you burned (BMR + steps + workouts). No food database to navigate. No "log this carrot" friction. Just the truth of the day. WHY DELTA • Deficit-first, not calorie-first. Most apps obsess over what you ate. Delta cares about • Honest math. BMR uses Mifflin–St Jeor. Intake includes a configurable safety margin because nobody logs perfectly. Steps and workouts come from Apple Health, not estimates. • Tiny. Three screens. No social feed, no streaks-as-pressure, no ads, no account. WHAT YOU GET • Today: your deficit ring, eaten vs. burned, steps toward your goal. • Trends: weight, deficit, hip, and energy charts over the diet window. • History: every past day, tappable for the full energy breakdown. • Morning log: weight, hip, energy — written back to Apple Health. • Goal: target weight + weekly pace, with the daily deficit math baked in. PRIVACY Delta stores everything locally on your device. Nothing is uploaded. No analytics, no servers, no account. Apple Health remains the source of truth — Delta only reads what you already have there. REQUIREMENTS • iPhone running iOS 17 or later • Apple Health permissions for dietary energy, macros, active energy, workouts, body mass, and steps
