Re vs Sync
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Re
This app offers a private and free way to track personal data locally on your device. It features a customizable interface and easy data exporting for analysis or backup, with no ads or subscriptions.
- Free to use, no ads or subscriptions
- Local data storage, no sign-up required
- Track any data, anytime
- Customizable interface
- Easy data exporting (CSV)
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Free: Free means free. No ads, no tiers, no upsells, and no subscriptions. Local: Your data stays on your phone, always. No sign up, no third-parties, no trackers. Tracking: Track what you want, when you want. Easy exporting allows you to backup your data or save a readable CSV to do your own analysis or print out. Period: Customizable interface allows you to hide anything you aren't interested in without losing any of your data.
Sync
A privacy-focused period tracker that stores all your data locally on your device. It offers a simple and ad-free experience for managing your menstrual cycle.
- Privacy-focused design
- Local data storage
- Ad-free experience
- Simple interface
- Cycle tracking
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Sync Period tracks cycles locally and supports private sharing with a partner or friend. Log periods, symptoms, moods, and notes; view your calendar and pattern summaries; set optional reminders; and import supported Flo, Clue, Drip, or generic CSV data after reviewing what Sync can recognize. Your cycle history is encrypted on your device. Private predictions adapt to your recent cycle history and confirmed corrections entirely on your device. Sync shows a likely-start window and confidence level, learns recurring pre-period patterns, and can use an enabled BBT signal or positive ovulation test without uploading those health details. Predictions become more cautious when history is sparse or variable. Partner sharing is optional and off by default. You choose which supported cycle details to share. Updates are end-to-end encrypted and require the complete private invite to open. Each encrypted relay update expires after no more than 30 days; active sharing renews that rolling expiration when a new update is published. Recent physical symptoms and flow, sex-drive and intimacy check-ins, and moods are three separate opt-ins that can each be turned off again. Intimate sharing is off by default and never indicates consent. Discharge, medications, written notes, and other sexual details remain private. Sync Period has no ads, no behavioral analytics SDKs, and no required account. You can export a private backup or permanently delete local app data at any time. Cycle predictions and pattern summaries are estimates. Sync Period does not provide diagnosis, contraception, or medical advice.
Screenshots
Verdict
The clearest difference is update cadence: Sync at every 3 weeks against Re's every 32 months. Re's advantage is iOS requirement (13.0 vs 15.1). On price, rating, ratings volume and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for Re against 5.0 for Sync. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
Re ships an update every 32 months, Sync every 3 weeks. The most recent releases landed on June 11, 2026 and September 2, 2026 respectively.
| Parameter | Re | Sync |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (1 ratings) |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 1 | 1 |
| Update frequency | Every 32 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 13.0 — better | 15.1 |
| Further details — not scored | ||
| Size | 22 MB | 41 MB |
| Age rating | 9+ | 12+ |
| Developer | apporeal | Wei Jian Wong |
Customer experience
Re
Sync
In-app purchases
Re
No in-app purchases
Sync
No in-app purchases









