Apple Health is optional. Everything you log in Ovessa works without it, and you can say no forever. Only water, glucose, sleep and steps need it, because they live in Apple Health. Connect it and two good things happen: your existing cycle history fills Ovessa from day one, and your metabolic data sits next to your cycle and symptoms.
Connecting
Connect during setup or later in Settings → Apple Health. iOS shows its own permission sheet, where you choose type by type what Ovessa may read and write. You can change that at any time in the Health app.
One honest limit: iOS deliberately hides from apps what you allowed them to read. Ovessa can only know that it asked, so “You’re linked to Apple Health” means the request went through, not that every type is shared. That’s Apple protecting you, not a bug.
What flows which way
- Both ways: cycle flow, weight, and seven symptoms: fatigue, bloating, acne, cramps, hair loss, mood and headache. What you log in Ovessa can be saved to your own Apple Health, and what’s already there comes into Ovessa. Apple Health has no type for excess hair, poor sleep or cravings, so those and your custom symptoms stay in Ovessa.
- Written only: your meals’ calories, carbs and protein.
- Read only: glucose from a CGM, sleep and steps. These come from sensors, and Ovessa has no business writing them.
- Water is the one metabolic number Ovessa writes, 250 mL per tap. It only ever deletes water it wrote itself.
If your CGM app writes glucose to Apple Health, Ovessa reads it and shows it next to your cycle, food and weight.
Your history from day one
The first sync brings in your full history. Cycle history already in Apple Health from another app arrives in Ovessa, so predictions don’t have to wait for three new cycles. After that, Ovessa reads only what changed: at launch, when you return to the app, as you leave it, a couple of seconds after you save something, and whenever you tap Sync now. It doesn’t sync in the background, and Sync automatically in Settings → Apple Health turns the automatic part off.
Edits and deletions
- Edits replace, never duplicate. Change a day in Ovessa and the matching Apple Health sample is replaced in place.
- Deleting in Ovessa removes what Ovessa wrote to Apple Health.
- Deleting in the Health app removes rows that came from Apple Health. For entries you made in Ovessa, it only stops sharing them: your diary keeps the entry, Apple Health’s deletion is respected, and one tap shares it again.
Privacy
Everything happens on your iPhone. Apple Health data is read in place and never copied to a server, never synced to iCloud by Ovessa and never sent to me. Apple’s rules also forbid using it for advertising or sharing it with third parties, and Ovessa does neither. Delete everything in Ovessa erases Ovessa’s own data but never touches Apple Health, which stays yours to manage in the Health app.
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