The 30-second summary
Stardust is a period, ovulation and pregnancy tracker that wraps cycle science in astrology — a moon calendar, zodiac "sign matchups", and lunar framing sit alongside the predictions. It went viral in 2022 and has passed a million downloads on Android. It is genuinely distinctive: no other mainstream tracker leans into the cosmic layer like this. It also ships a Partner Mode, so a significant other can follow her cycle and phases from their own phone.
Yuni is built for the partner as its whole reason to exist. Stardust's partner mode lets you watch her cycle; Yuni tells you what to do with it — a daily mode (Care, Energy, Connect, Calm, or PMS), what she may be feeling, and the words that help. It stays on your phone, needs no account, and never asks her to hand over a login.
| Stardust | Yuni | |
|---|---|---|
| Built for | The person tracking her cycle — astrology + science; a partner can follow along | Her partner — boyfriend, husband, fiancé |
| What the partner gets | A follow-along view of her cycle and phases | Daily guidance on what to do — 5 modes (Care · Energy · Connect · Calm · PMS) |
| "What to say" / "What not to say" scripts | No | Yes — phase-aware |
| Account required | Yes (sign-in) | No |
| Data storage | Cloud — synced through Stardust's servers (partner & friend sync need it) | On your phone — no cloud sync |
| Distinctive angle | Astrology, moon calendar, zodiac matchups, lunar cycle-syncing | Conversational, partner-relational — not cosmic or clinical |
| Platform | iOS + Android | iPhone (iOS 17+) |
| Pricing | Free + in-app purchases · Monthly $6.99 · Annual $29.99 | Free trial · Weekly $6.99 · Annual $39.99 |
When Stardust is the right choice
If the astrology is the point — if she likes seeing her cycle mapped to the moon, reading the zodiac matchups, and getting a cosmic story wrapped around the science — Stardust is genuinely the best in that lane, and nothing else mainstream does it. It's also on Android, cheaper on the annual plan, and its Partner Mode means a boyfriend can follow along without a second app.
If what she wants is one app that both tracks and gives a partner a light view in, Stardust covers it. The follow-along mode is real and it works. Where it stops is depth: it shows the partner where she is; it doesn't coach him through it.
When Yuni is the right choice
If you have ever sat on the sofa on a Tuesday night, clocked that she's gone quiet, and had no idea whether to reach over or give her the room, Yuni is for you. Following her cycle on a chart doesn't answer that. Yuni does: every morning it tells you what week she's in, what she may feel, and the one or two things that actually help.
That's the real line between the two apps. Stardust's partner mode lets you see where she is. Yuni is built around what you do next — the text that lands, the thing not to say, the twenty-minute wind-down before a hard week. It's the difference between a weather report and someone handing you a coat.
Privacy works differently in each, too. Stardust is cloud-based and account-based — it has to be, because the partner and friend cycle-syncing run through its servers. Yuni goes the other way: no account, no sign-in, no cloud. Your guidance lives on your phone, and when you pair, her cycle data never leaves her device. If "I downloaded something quietly and told no one" is the mode you want, that's the design.
The simple verdict
Get Stardust if…
She loves the astrology and the moon calendar, wants one app that tracks and lets a partner follow along, is on Android, or wants the cheaper annual plan. The cosmic layer is the whole appeal — and nothing else does it as well.
Get Yuni if…
You're the partner and you want to know what to do, not just what's happening. You want short daily guidance and phase-aware scripts instead of a chart to read. You don't want another account.
The real-world setup is usually Stardust on her phone, Yuni on his — they answer different questions, so they end up side by side rather than in competition.
How they work together
You can keep Stardust's partner mode to follow along and still run Yuni for the part Stardust doesn't do — telling you what actually helps this week. Yuni reads her phase from a paired source on her phone (or a single estimated cycle date if she doesn't track) and renders it as a daily nudge on yours. No third-party sync, no shared account.
Quick answers
Does Stardust have a partner mode?
Yes. Stardust has a Partner Mode that lets a significant other follow her cycle and phases from their own phone — a follow-along view inside her tracker. Yuni is a separate app built for the partner, focused on what to do each day rather than what to watch.
Is Yuni a Stardust competitor?
Not really. Stardust is a cycle tracker for the person menstruating, with astrology built in; Yuni is a daily-guidance app for her partner. Plenty of people happily use both.
Does Yuni do astrology or moon-cycle framing?
No. Yuni is practical and conversational — what she may feel this week and what helps. No zodiac, no moon calendar. If that's the part she loves about Stardust, keep Stardust for it.
What does it cost?
Free trial. Weekly $6.99 or Annual $39.99 after that. No ads, no data sale.
One tap. No account. If it's not useful, delete it and we never know you tried.
Stardust is a trademark of its respective owner. Yuni is not affiliated with or endorsed by Stardust.