The less you have to type, the more DayByDay can just be a mirror of your progress. Connecting Apple Health means your weight, steps, sleep, and workouts show up on their own — no double entry, no forgetting. It takes about a minute, and you stay in control of every permission.
Sync just happens
Once connected, Apple Health refreshes automatically every time you open DayByDay. There's nothing to tap — your data is usually up to date by the time you're looking at it.
Connecting Apple Health
- 1Open the You tab and tap Health Sync.
- 2Tap Connect Apple Health.
- 3On the system permissions sheet, switch on the data types you'd like DayByDay to read.
- 4Tap Allow. DayByDay pulls in your recent data right away.
Every permission is yours to choose
You can allow steps and sleep but keep logging weight by hand, or any mix you like. Grant some, hold back others, and change your mind anytime — DayByDay only ever reads what you've said yes to.
What syncs in
- ✦Weight — readings from Apple Health or a compatible smart scale
- ✦Steps — daily step count from your iPhone or Apple Watch
- ✦Sleep — stages (awake, REM, core, deep) from Apple Watch
- ✦Workouts & active calories — exercise sessions you've recorded
- ✦Heart rate — including resting heart rate measured overnight
- ✦Blood oxygen (SpO2), VO2 max, blood glucose, and more, where your devices write them to Health
Your manual entries are protected
DayByDay de-duplicates by date — it keeps one entry per day and won't pile up copies from repeated syncs. Most importantly, anything you logged by hand is never overwritten by automatic sync. If you typed a weigh-in this morning, that's the one that stands, even if Apple Health also has a reading for the day.
Auto-sync vs. logging it yourself
Steps, calories, and workout minutes come in automatically from Apple Health. For anything that wasn't captured — a strength session, a walk your phone missed — just log it in Track → Activity. Both live happily side by side.
O2 Ring for overnight oxygen
If you wear a Wellue / Viatom O2 Ring, DayByDay can bring in detailed overnight blood-oxygen data that goes beyond what an Apple Watch captures — average and lowest SpO2, oxygen dips per hour, an overall O2 score, and overnight heart rate. The O2 Ring and Apple Watch work together: oxygen data from the ring sits alongside your Watch sleep stages, so you get the best of both.
Heading to a sleep or GLP-1 appointment?
Overnight oxygen and sleep stages are exactly the kind of detail a clinician appreciates. You don't have to read numbers off your phone — DayByDay can fold them into a doctor-ready PDF for you. See Reports & your doctor.
On Android
DayByDay reads from Android Health Connect for weight, steps, sleep, and workouts the same way it reads Apple Health on iPhone. Connect it from the same You → Health Sync screen on an Android device. A few of the newest data types are still rolling out to Android — if something you expect isn't flowing yet, you can always log it by hand in the meantime.
If sync seems stuck
- 1On iPhone, open Settings → Privacy & Security → Health → DayByDay and confirm the data types you want are switched on (iOS occasionally resets these after an update).
- 2Open the Health app and check that your source device (Apple Watch, scale) is actually writing the data there — DayByDay can only read what's already in Health.
- 3Force-quit DayByDay and reopen it; sync runs on launch, which clears most stuck syncs.
- 4Still off? Reach out at support@mydaybyday.app and tell us what you're seeing.
Your health data stays private
Data synced from Apple Health is stored securely in your personal, encrypted account. DayByDay never sells your health data and never shares it for advertising. You can export or delete all of it anytime — see Privacy & legal.