Frequently Asked Questions

When you open SyncMate for the first time you will see the onboarding screen. Follow these steps:

1. Enter the last period start date. Use the calendar picker to select the date your partner’s most recent period began. If you’re not sure of the exact date, pick the closest estimate — you can always update it later by logging a new period.
2. Give consent. Toggle the consent checkbox to confirm your partner is aware you are using the app. SyncMate is designed to be a shared, communicative tool — not a secret tracker.
3. Tap “Get Started.” The button becomes active once the consent box is checked. SyncMate will immediately calculate the current cycle phase and show today’s insight on the home screen.

SyncMate helps you support your partner day-to-day by showing you which phase of her menstrual cycle she is likely in and what that typically means for how she might feel, what hormones are at play, and how you can best show up for her.

Once you log a period start date the app:

• Calculates today’s estimated cycle phase
• Shows a daily insight card with mood context, hormone notes, care suggestions, and food/activity ideas
• Displays a visual phase timeline for the full cycle
• Predicts the next period start date based on her average cycle length
• Learns from your daily feedback to sharpen future predictions

No. SyncMate is a supportive awareness tool for partners. The phase descriptions, hormone notes, care suggestions, and all other content in the app are general informational material based on typical cycle biology — they are not personalised medical guidance.

If your partner experiences severe PMS symptoms, irregular cycles, painful periods, or any other health concerns, please encourage her to consult a qualified healthcare professional. The app explicitly notes this in the Late Luteal phase description when PMS symptoms are discussed.

See the Terms of Use for the full medical disclaimer.

There are two ways to log a period start date:

From the home screen (most common):

1. Tap the red “Log New Period Start” button at the bottom of the home screen.
2. A sheet slides up showing a calendar date picker.
3. Scroll to the correct date — this should be the first day of bleeding, not spotting.
4. Tap “Save” (the green checkmark button). The sheet closes and the cycle timeline updates immediately.

During first-time setup: The onboarding screen includes the same date picker. Enter the most recent period start date to get going from day one.

After saving, the home screen metrics bar updates to show the revised average cycle length and next predicted period date. The phase timeline also redraws to reflect the new data.

Yes — and logging multiple periods is the best way to improve accuracy. Each time you log a new period start, SyncMate adds that date to a running list. Once you have two or more dates logged, the app calculates the average number of days between them and uses that as the cycle length for future predictions.

For example:

• Period logged March 1, then April 2 → 32-day average cycle
• Period logged again May 3 → average updates to 31 days

The more logged periods you have, the more stable and accurate the average becomes. You can see the current average cycle length in the metrics row on the home screen.

Currently, the easiest fix is to log the correct date as a new entry. If the incorrect date is significantly off, you can reset all data in Settings → Data → Reset All Data and start fresh with the correct dates. This clears period history, feedback history, and resets the tuning adjustments.

SyncMate divides the menstrual cycle into six distinct phases. Starting from the last logged period start date, the app places each phase in sequence based on known biological timing and your personal cycle length. Here is how the math works:

1. Cycle length is either 28 days (default) or your personal average once two or more periods are logged.
2. Next period start = last period start + average cycle length.
3. Ovulation window is placed luteal length days before the next period start. The default luteal phase is 14 days, so ovulation is estimated around cycle day 14 (in a 28-day cycle) — but this adjusts to your data over time.
4. PMS window starts PMS length days before the next period (default: 5 days).
5. The follicular phase fills the gap between the end of menstruation and the ovulation window, split evenly into Early and Late Follicular.

Today’s phase is determined by where the current date falls within this framework.

SyncMate tracks six phases that together cover a complete menstrual cycle:

Accuracy depends on how much data you have logged and how regular the cycle is:

• First period logged (1 entry): SyncMate uses a standard 28-day cycle with default phase lengths. Predictions will be approximate until more data is available.
• Two or more periods logged: The app calculates a personal average cycle length. Next-period estimates improve significantly.
• Many periods + consistent feedback: The TuningEngine makes small automatic adjustments to the luteal and PMS windows based on your thumbs-up / thumbs-down feedback. Over time the phase boundaries adapt to her individual pattern.

Cycle length and phase boundaries naturally vary from month to month due to stress, travel, illness, and other factors. No app can predict to the exact day — treat all dates as estimates within a window of ±2–3 days.

The TuningEngine is SyncMate’s adaptive prediction system. It watches your daily feedback (the thumbs-up / thumbs-down on the home screen) and silently fine-tunes two parameters over time:

• Luteal delta (Δ): Shifts the estimated ovulation window earlier or later by up to 2 days in either direction.
• PMS delta (Δ): Shifts the start of the PMS window earlier or later by up to 3 days.

How tuning works:

1. Every day you tap a thumbs-up or thumbs-down, SyncMate records whether today’s phase felt accurate.
2. The TuningEngine looks at up to 60 recent feedback entries.
3. If 60% or more of feedback in the 3 days before a phase boundary is negative, the boundary shifts earlier (the phase was starting too late).
4. If 60% or more of feedback in the first 2 days inside a phase boundary is negative, the boundary shifts later (the phase was starting too early).
5. Adjustments require at least 3 qualifying feedback entries before triggering — preventing single-day noise from skewing predictions.

The thumbs-up / thumbs-down bar on the home screen is the primary signal the TuningEngine uses to improve predictions. The more consistently you rate each day, the faster the app learns her personal rhythm.

What “accurate” means: Did today’s phase description match how she was actually feeling or behaving today? If her energy, mood, and the context card felt spot-on, tap thumbs-up. If it felt off — for example if the PMS card appeared but she seemed fine — tap thumbs-down.

You only get one feedback entry per day. If you miss a day that is fine — the engine works with whatever data it has.

Open Settings (the gear icon on the home screen) to find the following adjustable parameters under Cycle Settings (Base):

• Menstruation length: How many days the period typically lasts (2–8 days, default 5).
• Luteal length: The number of days between predicted ovulation and the next period start, used to estimate the ovulation window (8–18 days, default 14).
• PMS window: How many days before the next period the Late Luteal / PMS phase begins (2–10 days, default 5).

If you know from experience that her PMS consistently starts 7 days before her period, you can set the PMS window to 7. These base values are the starting point; the TuningEngine then applies small automatic deltas on top.

Under Tuned Adjustments (Auto) you can see the current Luteal Δ and PMS Δ values applied by the TuningEngine. Tap Reset Tuning to clear them back to zero while keeping your base settings.

Each day SyncMate shows a suggestion card on the home screen tailored to the current cycle phase. Every suggestion covers five dimensions of support:

• Food — specific meals or nutrients that match the phase’s hormonal needs
• Activity — movement or date ideas that suit her energy level
• Care — practical things you can do around the home or for her comfort
• Communication — how to phrase check-ins or conversations for this phase
• Lead-in — a one-line framing cue so you know the right tone before you engage

SyncMate rotates through the suggestion library so you don’t see the same card two days in a row. The app remembers the last 12 suggestions shown and avoids repeating them until the library cycles through.

Here are representative examples drawn from each phase in the suggestion library:

The full library contains multiple suggestions per phase. SyncMate picks one each day, weighted to avoid recent repeats, so the card stays fresh across the entire cycle.

Each phase has distinct hormonal patterns that interact with nutrition. SyncMate’s suggestion library matches food recommendations to those patterns:

• Menstruation — iron and vitamin C to offset blood loss; omega-3 and magnesium to help with inflammation and cramps
• Follicular — lean proteins and fiber for steady energy as estrogen climbs
• Ovulation window — zinc-rich foods to support the LH surge and overall hormonal activity
• Luteal — complex carbs and magnesium to help stabilise mood as progesterone peaks then drops
• PMS (Late Luteal) — dark chocolate and magnesium-rich greens, which research associates with cramp and mood relief

SyncMate can send a daily reminder with the current phase insight. To set this up:

1. Go to Settings (gear icon, top-right of home screen).
2. Under Notifications, use the steppers to choose the Hour and Minute you want the daily notification delivered.
3. Tap “Reschedule Daily Notification.”

If you have not granted notification permission yet, iOS will prompt you the first time you tap the reschedule button. You can also grant or revoke permission at any time via:

iOS Settings → Notifications → SyncMate → Allow Notifications.

Each notification contains three pieces of information pulled directly from the home screen’s current insight:

• Title: “Today’s Cycle Insight”
• Subtitle: The day-label for the current phase (for example, “Day 14 — Ovulation Window”)
• Body: The phase message and today’s wellness suggestion combined into one line

If no period start date has been logged yet, the notification body will instead read: “Add your partner’s last period start date to get tailored daily tips.”

Work through these steps in order:

1. Check iOS notification permission.
   Go to iPhone Settings → Notifications → SyncMate and confirm Allow Notifications is toggled on. If SyncMate does not appear in the list, open the app once and tap “Reschedule Daily Notification” in Settings — this triggers the iOS permission prompt.
2. Check Focus / Do Not Disturb.
   Active Focus modes (Sleep, Driving, Do Not Disturb) silently block notifications. Either disable Focus or add SyncMate as an allowed app in iPhone Settings → Focus → [your active mode] → Allowed Apps.
3. Reschedule after changing the time.
   If you updated the Hour or Minute steppers in SyncMate Settings but did not tap “Reschedule Daily Notification” afterwards, the old time (or no notification) is still active. Always tap the button to apply any time change.
4. Check that a period start date is logged.
   SyncMate schedules the notification during the same action as “Reschedule Daily Notification.” If no period has been logged the notification will still fire but the body text will only show the onboarding prompt, which may look blank on some lock screen layouts.

If notifications still do not appear after completing these steps, try deleting and reinstalling the app, then re-entering your data and re-scheduling the notification.

SyncMate uses local push notifications only. This means:

• The notification is created entirely on your device — no server, no network call, no third-party service is involved
• No notification content (phase name, suggestion text, or anything else) ever leaves your iPhone
• Notifications work without an internet connection
• SyncMate has no analytics SDK, no push notification provider (APNs is only used for remote push — SyncMate does not register for remote notifications), and no backend that could receive or store notification events

The notification is scheduled using iOS’s UNCalendarNotificationTrigger with a daily repeating time. iOS fires it locally at the right time each day without contacting any external system.

No. SyncMate collects zero data. The app has no account system, no backend server, no analytics SDK, and no network calls of any kind. Everything you enter stays exclusively on your iPhone.

Specifically, the app stores the following information — and only on your device:

• Period start dates you have logged
• Daily feedback entries (thumbs-up / thumbs-down)
• Cycle settings (menstruation length, luteal length, PMS window)
• TuningEngine delta values
• Recent suggestion history (to avoid repeats)
• Notification preferences (scheduled time)

None of this information is ever transmitted anywhere. SyncMate does not even request network access.

SyncMate stores all data using UserDefaults, the iOS standard local key-value storage. This is a sandboxed storage area that belongs exclusively to the SyncMate app on your iPhone. No other app can read it.

UserDefaults is stored inside the app’s private container on the device file system. It is:

• Not synced to iCloud — SyncMate does not opt in to iCloud key-value or iCloud Drive sync
• Not backed up to iTunes / Finder by default — UserDefaults is included in iOS device backups if you have iCloud Backup or local device backup enabled, but no data leaves your device during normal use
• Deleted automatically when you uninstall the app

Because SyncMate collects no personal data and operates entirely on your device, the usual GDPR and CCPA obligations simply do not arise:

• No data processing by us — we never receive, store, or process any information about you or your partner. There is no server-side processing to regulate.
• Right of access — all data is already on your device. Open the app and everything you have entered is visible to you.
• Right to erasure — tap Settings → Data → Reset All Data to permanently delete everything from your device instantly. Alternatively, uninstalling the app removes all data.
• Data portability — there is no export feature because there is no central system to export from. Your data lives on your device.
• No consent required for tracking — SyncMate does not track you, so no ATT (App Tracking Transparency) prompt is shown.

You have complete and exclusive control over your data at all times. We have no ability to access it even if legally compelled.

SyncMate is a single-device, local-only app. There is no account system and no cloud sync, so your data cannot be automatically moved to a new device or shared across multiple iPhones.

When you get a new iPhone: If you restore from an iCloud Backup or a local iTunes/Finder backup, your SyncMate data is typically included in the backup and will be restored. However, this depends on your backup settings.

What does not work:

• Logging in to access your data on a second iPhone
• Syncing period data between two devices in real time
• Sharing cycle data with a partner who has their own iPhone

Why this is by design: Local-only storage means your partner’s sensitive health information never travels over a network. The trade-off is that cross-device sync is not supported.

No. SyncMate is built entirely with Apple’s first-party frameworks — SwiftUI and the iOS standard library. It uses no third-party code, libraries, or services of any kind. In particular:

• No analytics or crash reporting SDK (no Firebase, Mixpanel, Amplitude, Crashlytics, etc.)
• No advertising or attribution SDK (no Facebook, Adjust, AppsFlyer, etc.)
• No A/B testing or feature-flag service
• No remote configuration or content delivery service
• No push notification provider — notifications are scheduled locally using iOS’s built-in UserNotifications framework, not via APNs remote delivery

This keeps the app small, fast, and free of any external data dependencies.

All data — period start dates, feedback entries, cycle settings, and tuning values — is stored in UserDefaults on your iPhone only. SyncMate has no account system, no backend server, and no analytics. Nothing is transmitted over the network.

If you delete the app, all data is removed from your device. There is no cloud backup.

Read the full Privacy Policy for details.

To erase all stored data:

1. Open Settings (gear icon on the home screen).
2. Scroll to the Data section.
3. Tap “Reset All Data” (shown in red).

This removes all period start dates, all daily feedback, all suggestion history, and resets the TuningEngine deltas to zero. The app returns to the onboarding screen so you can start fresh.

SyncMate saves data to UserDefaults every time you make a change. If data appears missing, work through these steps:

1. Check available iPhone storage.
   Go to iPhone Settings → General → iPhone Storage. If your device is nearly full (under ~500 MB free), iOS may fail to write to UserDefaults. Free up space by deleting unused apps or media, then re-enter the missing data in SyncMate.
2. Check if you accidentally reset data.
   SyncMate’s Settings → Data → Reset All Data wipes everything immediately. If the app is showing the onboarding screen, a reset may have been triggered. Re-enter your period start dates from the home screen.
3. Make sure you are not confusing devices.
   SyncMate data is local to the device it was entered on. If you recently switched to a new iPhone and did not restore from backup, the data from your previous device will not be present.
4. Force-quit and reopen the app.
   Swipe up from the home bar (or double-tap the home button) to open the app switcher, swipe SyncMate away, then reopen it. This forces the app to reload from storage.
5. Reinstall if the issue persists.
   As a last resort, delete SyncMate and reinstall from the App Store. Note: this will erase all data. After reinstalling, re-enter your period history manually.

Prediction accuracy improves with more data. Here is what affects it and how to help the app learn faster:

Likely causes of inaccuracy:

• Not enough cycle data yet. With only one logged period, SyncMate defaults to a standard 28-day cycle. Every additional period you log refines the personal average cycle length, which directly improves all phase timing.
• No feedback given. The TuningEngine needs thumbs-up / thumbs-down entries to shift the luteal and PMS window boundaries. Without any feedback, the phase boundaries stay at their defaults.
• Natural cycle variation. Cycles shift in length due to stress, travel, illness, hormonal changes, and other factors. No app can predict to the exact day — a ±2–3 day window is normal.

Steps to improve accuracy:

1. Log each new period start date promptly when it begins.
2. Give daily feedback consistently — even a few weeks of regular thumbs-up / thumbs-down ratings gives the TuningEngine enough signal to adjust.
3. If you know her PMS typically starts earlier or later than the default, adjust the PMS window setting manually in Settings → Cycle Settings (Base).
4. Check Settings → Tuned Adjustments (Auto) to see if the TuningEngine has already made adjustments. If the deltas look off, tap Reset Tuning and let it re-learn from recent feedback.

Work through these steps in order:

1. Update to the latest iOS version.
   Go to iPhone Settings → General → Software Update. SyncMate is built for current iOS versions and some older iOS releases have known SwiftUI rendering bugs that can cause crashes.
2. Update SyncMate.
   Open the App Store → Account → Updates and check whether a SyncMate update is available. Bug fixes are delivered through App Store updates.
3. Force-quit and restart.
   Swipe up from the home bar (or double-tap the home button), swipe SyncMate away, then reopen it. This clears any in-memory state that may have become inconsistent.
4. Restart your iPhone.
   Hold the side button and a volume button, slide to power off, wait 30 seconds, and restart. This clears system-level caches that can sometimes affect app behaviour.
5. Delete and reinstall the app.
   If the crash happens every time the app opens, a clean reinstall is the most reliable fix. Long-press the SyncMate icon, tap Remove App → Delete App, then reinstall from the App Store.
   Deleting the app permanently erases all your data. Before reinstalling, note your period start dates so you can re-enter them after reinstalling.

If the crash persists after a clean reinstall, please contact support and describe exactly what you tapped before the crash occurred. This helps identify the cause quickly.