Know Her vs
Selin

Selin doesn't have a weak partner feature. It has none at all — zero screens, zero data, zero reason to open it.

★  Actually built for you
Know Her period tracker app — home screen widget showing her cycle phase

If you downloaded Selin hoping to understand her cycle, you'd be using an app that has nothing to tell you.

Selin is a period, ovulation, and fertility app for women to log symptoms, cycle length, and health signals about themselves. That's the entire product. No partner view, no sharing feature, no screen that was ever meant for you to look at. It's not that Selin does the job worse than Know Her — it doesn't attempt the job at all. Selin answers "how is my cycle going?" for her. Know Her answers "what should I expect from her today?" for you, which is the question you actually came here with.

Who each app is actually for

One of these was never meant to answer your question.

Selin

  • Built for her to self-track. Symptom logging, fertility charts, ovulation predictions, cycle history — all from her point of view.
  • No partner mode. There's no feature that shows any of this to someone else.
  • You'd have to read her phone. The only way to "use" Selin as a partner is to open her app yourself — not private, not built for that.

A genuinely good app for tracking a cycle — just not yours to use, and not built to tell you anything.

Know Her

  • The date her last period started. That's it. You set it up, you own it, you control it.

No account from her, no reading her phone. Know Her is fully yours, from day one — 100% offline, locked behind Face ID if you want.

Feature comparison

Know Her vs Selin, side by side.

Know Her Selin
Built for male partners ✓ Purpose-built ✗ Built for her, self-tracking only
Has any partner-facing view ✓ Yes — the whole app ✗ Doesn't exist
Requires her account/participation ✓ No Irrelevant — it's her app to begin with
100% offline ✓ Yes Depends on her account settings
Home screen widget for you ✓ Yes ✗ No — nothing built for a partner
Phase-change notifications for you ✓ Yes — day before ✗ No
Face ID / biometric lock ✓ Yes Her app, her settings
Private notes on the calendar ✓ Yes — offline, only yours ✗ No
Language designed for men ✓ Plain, practical Symptom and fertility terminology, for her
Predictions self-calibrate ✓ Yes — learns her cycle Learns from her own logged symptoms
Your price $2.99/mo — 14-day free trial N/A — not something you'd subscribe to

Design intent matters

What the app was built to solve changes everything about how it works.

Know Her

  • ✓ Phase names and descriptions written for men
  • ✓ Dashboard: energy, mood, tips in plain language
  • ✓ Practical daily guide — what she might need from you
  • ✓ Calendar built for at-a-glance reading, not medical logging
  • ✓ Widget: one-tap phase check from the home screen
  • ✓ Notifications timed so you're prepared, not caught off guard

Selin

  • ✓ A genuinely capable tracker — for her own use
  • ✗ No dashboard, widget, or notifications for a partner
  • ✗ Health articles written for the woman tracking her body
  • ✗ No concept of "what should the partner expect"
  • ✗ Nothing designed for a man to check in a few seconds
  • ✗ No private notes layer for a partner

Privacy: local vs cloud

Where your data lives is a design decision, not a technicality.

Know Her stores everything on your device. Period history, notes, settings — none of it is uploaded anywhere. There is no server holding her cycle data. You can lock the app behind Face ID, and the data stays entirely yours.

Selin is her own tracking tool, with her own account and her own privacy settings. There's no version of it built for a partner to view — which also means there's no privacy model to compare, because you were never meant to be on the other side of it.

Price comparison

What it actually costs you.

Know Her Free to download — full access for 14 days

Then $19.99/year (or $2.99/month). One app, one subscription — yours. No other accounts or plans required. Cancel anytime.

Selin $47.95 her premium, per year (or $7.99/mo)

This is what she'd pay to track her own cycle — there's no partner tier because there's no partner feature.

Only one of these is actually built for you to pay for.

Common questions

About choosing between Know Her and Selin.

No. Selin is a period and ovulation tracker built for women to log their own cycle, symptoms, and fertility signals. It has no partner-facing feature, no shared view, and nothing designed to help a man understand what to expect from her cycle. Know Her was built from day one for the male partner.
Not really. Selin has no partner or sharing mode — it's a self-tracking app for the woman using it. You'd have to open her app and read her data yourself, which isn't what it's built for and isn't private for her. Know Her is designed specifically so you can follow her cycle without needing her account at all — you just enter the date her last period started.
Yes. Know Her stores everything on your device — no account, no cloud, no sync. All data stays on your phone.
Know Her is free to download, with a 14-day trial that includes full access, then $19.99/year (or $2.99/month). Selin's own premium plans run around $47.95/year or $7.99/month, but that's pricing for her to track her own health — it has nothing to do with a partner using it, because that feature doesn't exist.
No. Know Her works entirely from information you enter yourself — no account for her, nothing to install, nothing to share. You just need the date her last period started. She doesn't even need to know you're using it.
Yes. Everything stays on your phone — no account, no cloud, no sync, nothing to leak. You can lock the app with Face ID or biometrics for extra privacy on top of that.
You get 14 days of full access, completely free. After that, Know Her runs on a simple subscription — monthly or annual. Cancel anytime directly in your App Store settings.
No. Know Her is designed to help you understand and plan around her cycle — it's not a medical device, diagnostic tool, or method of contraception. For health decisions, always consult a healthcare professional.

More comparisons

See how Know Her stacks up against other apps.

Know Her vs Flo for Partners Know Her vs Clue Connect Know Her vs Stardust Know Her vs Maya Know Her vs Yuni Know Her vs Phases Know Her vs GF Tracker Know Her vs DuoSync Know Her vs Mayday

Available on
iOS & Android.

Free for 14 days.

No commitment. Cancel anytime.

Download on the App Store
Get it on Google Play