Choose Stardust if you love moon cycles, astrology and manifesting, want to track alongside a group of friends, or want a pregnancy mode. Choose SheSync if you want plain-language science without the astrology, a companion character that makes logging fun, and a simple way to share your cycle with a partner, parent or friend who'll actually understand it.
We make SheSync, so read this with that in mind. Everything we say about Stardust comes from its own App Store listing.
Stardust: cycle tracking with a cosmic twist
Stardust has been on the App Store since 2020 and is made by Stardust App LLC. Its listing describes it as a period, pregnancy and hormone tracker that combines science, ancient wisdom, astronomy and AI. Features it lists include:
- personal daily insights, and predictions for your period, PMS symptoms, cravings, moods and fertility;
- cycle syncing and period tracking with friends, and inviting partners to follow your cycle;
- a moon calendar, lunar-menstrual "synchronicity" for manifesting goals, and the folklore behind your cycle;
- a pregnancy mode with augmented-reality baby size, trimester affirmations and zodiac match-ups;
- a promise never to sell or divulge your data, from a company founded and led by women.
It's free to download and has a 4.7-star average from nearly 10,000 ratings on the Australian App Store.
SheSync: plain-language science, built for sharing
SheSync launched in 2025 and is made by Digital Sauce in Melbourne. Its listing and our app page describe:
- a cute companion character that reacts to your cycle and your logs;
- predictions for periods, ovulation and your fertile window, learned from your own history;
- quick logging of flow, symptoms, mood and cravings, with each cycle flagged regular or irregular against your own baseline;
- plain-language explanations of each phase, with no astrology;
- sharing with a partner, parent or friend, an AI assistant that runs on our own servers, widgets and encrypted cloud backup with SheSync Pro;
- no advertising or cross-app tracking, and on the free plan your logs stay on your phone.
Tracking, predictions, logging and insights are free. SheSync is available in ten languages. It has a 5.0-star average on the Australian App Store, from a much smaller number of ratings.
Side by side
| Stardust | SheSync | |
|---|---|---|
| On the App Store since | 2020 | 2025 |
| Approach | Science plus moon cycles, astrology and manifesting | Plain-language science, no astrology |
| Sharing | Track with friends; invite partners | Partner, parent or friend (SheSync Pro) |
| What the other person gets | Check listing | Your phase, predicted dates and symptoms, with plain-English explanations |
| Companion character | Not in its listing | Reacts to your logs |
| Pregnancy mode | Yes | Not in its listing |
| AI | Mentioned in its listing | AI assistant on our own servers (SheSync Pro) |
| Where your logs live | See its privacy policy | Free plan: only on your phone. Pro: encrypted cloud backup |
| Price | Free to download | Free tracking; SheSync Pro subscription |
From each app's App Store listing and our own documentation, checked October 2026. Apps change often, so check the current listing before you decide.
Which should you choose?
- You enjoy astrology, moon phases and manifesting: Stardust.
- You're pregnant or trying to conceive and want a pregnancy mode: Stardust.
- You want your partner or parent to understand your cycle without a biology lecture: SheSync.
- You want explanations grounded in science, in plain English: SheSync.
- You'd rather your logs never leave your phone: SheSync's free plan.
Comparing more apps? See Flo and Clue alternatives, the best period trackers for couples and SheSync vs Apple Health.
Frequently asked questions
Is SheSync or Stardust better?
It depends on what you want. Stardust blends cycle science with moon cycles, astrology and manifesting, lets you track with friends and partners, and has a pregnancy mode. SheSync sticks to plain-language science, has a companion character that reacts to your logs, and lets you share your cycle with a partner, parent or friend with SheSync Pro.
Can I share my cycle with friends in Stardust and SheSync?
Yes, in both. Stardust's listing describes cycle syncing and period tracking with friends, and inviting partners. In SheSync, sharing with a partner, parent or friend is part of SheSync Pro, and the person you invite sees your phase, predicted dates and logged symptoms with plain-English explanations.
Does SheSync use astrology or moon cycles?
No. SheSync explains your cycle with plain-language science and simple everyday actions. If moon calendars and astrology are part of what you enjoy, Stardust is built around them.
Is Stardust free?
Stardust is free to download from the App Store. Check its listing for any paid features. SheSync's tracking, predictions, symptom logging and insights are free, and SheSync Pro adds sharing, the AI assistant, widgets and encrypted cloud backup.
Sources
- Stardust Period Tracker, App Store listing
- SheSync - Period Tracker, App Store listing
- SheSync privacy policy, Digital Sauce
Last updated 9 October 2026. SheSync is a tracking and education tool, not a medical device or contraceptive method. For medical questions about your cycle, talk to your doctor.