Know Her vs
Phases

Phases hands you a biology curriculum and an account to log into. Know Her just tells you what to expect from her today.

★  No homework required
Know Her period tracker app — home screen widget showing her cycle phase

Phases makes you study the menstrual cycle before it tells you anything. Know Her just answers the question.

Phases opens with a login screen — email, password — before it opens with anything about her. Then a Learn tab full of hormone charts, symptom lists, and foods that "may help," which sounds like it's for men, but reads like it was written for someone studying the cycle in general, not for a man trying to figure out what his partner needs from him today. None of that biology answers the one question you actually opened the app for. Know Her skips all of it: no account, no curriculum. You open the app and it already tells you her phase, her mood, and what she might need from you — nothing to log into, nothing to study first.

Two different approaches to the same problem

Both are built for men. They solve it differently.

Phases

  • You need to create an account — email and password required to log in, confirmed directly in the app.
  • Teaches you the biology — hormone changes, symptoms, and support tips per stage, via a Learn tab.
  • Visual timeline of her cycle, not a daily practical dashboard.
  • No sign it self-calibrates to her specific rhythm over time.

An account to make, a curriculum to get through — and still no answer to what she actually needs from you.

Know Her

  • The date her last period started. No account, no login, no biology lesson — just the answer.

Translates her cycle into her mood, her energy, and what she might need — and gets more accurate as you use it.

Feature comparison

Know Her vs Phases, side by side.

Know Her Phases
Built for male partners ✓ Purpose-built ✓ Purpose-built
She needs no app or account ✓ Yes ✓ Yes
You need an account to log in ✓ No — nothing to sign up for ✗ Yes — email + password required
Daily practical guidance ✓ Mood, energy, what to expect Educational content, per stage
Predictions self-calibrate ✓ Yes — learns her cycle ✗ No sign of self-calibration
100% offline ✓ Yes ✗ Account login suggests cloud-backed
Home screen widget ✓ Yes ✗ Not listed
Phase-change notifications ✓ Yes — day before ✗ Not listed
Private notes on the calendar ✓ Yes — offline, only yours ✗ No
Your price $2.99/mo — 14-day free trial Free

Design intent matters

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

Know Her

  • ✓ Skips the biology lesson entirely
  • ✓ Dashboard: energy, mood, tips in plain language
  • ✓ Self-calibrates to her specific cycle over time
  • ✓ Widget: one-tap phase check from the home screen
  • ✓ Private notes and reminders on the calendar
  • ✓ Face ID lock for extra privacy

Phases

  • ✗ Requires an account — email and password to log in
  • ✓ Learn tab: hormones, symptoms, support tips per stage
  • ✗ Visual timeline, not a daily practical dashboard
  • ✗ No indication predictions improve over time
  • ✗ No home screen widget found
  • ✗ No private notes layer

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). Self-calibrates over time, home screen widget, Face ID lock, private notes.

Phases Free no premium tier found

No cost, with a genuinely useful biology primer — but no sign of daily practical guidance or self-calibration.

Phases is free. Know Her is less than $2/month and skips the lesson entirely.

Common questions

About choosing between Know Her and Phases.

Phases teaches you the biology of the menstrual cycle — hormone changes, symptoms by stage, foods that may help — through a dedicated Learn tab. Know Her skips the education and translates her cycle directly into what matters: her mood, her energy, and what she might need from you today. Neither approach is wrong, but Know Her is built for men who want the answer without the lesson.
Yes. Phases requires you to log in with an email and password before you can use the app — confirmed directly in the app's sign-in screen. Know Her requires no account at all, from you or from her.
There's no indication that it does. Phases presents cycle information as a visual timeline but doesn't appear to adjust its predictions as you log more of her periods. Know Her self-calibrates — every confirmed period makes its predictions more accurate to her specific rhythm.
Yes, Phases is free with no premium tier found in its current listing. Know Her is free to download, with a 14-day trial that includes full access, then $19.99/year (or $2.99/month), and in exchange self-calibrates to her specific cycle and includes a home screen widget, phase-change notifications, and private notes.
Yes. Know Her stores everything on your device — no account, no cloud, no sync. All data stays on your phone. You can lock it with Face ID or biometrics for extra privacy.
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

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Available on
iOS & Android.

Free for 14 days.

No commitment. Cancel anytime.

Download on the App Store
Get it on Google Play