Everything you need to know about Fern.
Yes, 100%. Fern stores all your data locally on your device using Apple's SwiftData framework. We have no servers, no accounts, and no analytics. We literally cannot see your data because it never leaves your phone. Our App Store privacy label confirms: "Data Not Collected."
No. Fern requires no account, no email, no registration of any kind. Open the app and start tracking immediately. This is intentional - we don't want to know who you are.
Decoy Mode is a safety feature. When App Lock is enabled, entering any incorrect passcode will open the app showing fake/empty data instead of showing an error. This provides plausible deniability - if someone pressures you to unlock the app, you can enter the wrong passcode and they'll see empty data, while your real data remains hidden and protected.
Yes. Fern offers optional iCloud sync, which is disabled by default. When you enable it in Settings, your data syncs to your private iCloud account via Apple's CloudKit. Only you can access this data through your Apple ID. Data is encrypted in transit and at rest. You can disable sync at any time.
Go to Settings > Backup & Restore > Create Backup. You'll set a password, and Fern will create an AES-GCM encrypted backup file that you can save anywhere (Files, AirDrop, email, etc.). To restore, use "Restore Backup" and enter your password. You can also enable iCloud sync for automatic cloud backup.
Fern uses a transparent, simple algorithm. We average your last 6 cycle lengths to predict your next period. The fertile window is calculated by estimating ovulation at 14 days before your next predicted period, with the fertile window spanning 5 days before ovulation through 1 day after. The more cycles you log, the more accurate predictions become.
Important: Predictions are estimates and should not be used as birth control or the sole method of conception planning.
Fern can make predictions from your very first logged cycle using the average 28-day cycle as a baseline. However, predictions improve significantly after 3-6 logged cycles, as the algorithm uses your personal data instead of averages.
Fern includes 11 symptom types across categories: Pain (Cramps, Headache, Backache, Breast Tenderness), Physical (Bloating, Fatigue, Acne, Cravings, Nausea), and Other (Discharge). Each symptom can be rated on a 1-3 severity scale. Free users can log 5 symptoms per day; Premium unlocks unlimited logging.
Go to Settings > Tracking Mode > Pregnancy. You'll be guided through setup where you can enter your due date, last period date, or conception date. Fern will calculate your current week and provide week-by-week tracking from that point forward. You can switch back to period tracking at any time.
Pregnancy mode offers: week-by-week baby development information with size comparisons, a kick counter with timer and haptic feedback, daily health logging (weight, blood pressure, symptoms, moods), prenatal appointment scheduling, bump photo diary, milestone tracking, and pregnancy-specific insights. All 42 weeks of development data are included for free.
The kick counter records each tap you make, along with timing. It uses a standard 10-kick goal within a 2-hour session, which is a common clinical guideline. However, always follow your healthcare provider's specific instructions for kick counting.
Premium unlocks: unlimited daily symptoms (vs. 5 in Free), 5 additional beautiful themes (Lavender, Sage, Ocean, Sunset, Midnight), PDF reports you can share with your doctor, advanced cycle statistics with charts, and cycle length trend analysis.
Lifetime ($6.99): A one-time purchase that permanently unlocks all premium features. Best value - pay once, own forever.
Monthly ($1.99/month): An auto-renewable subscription that gives access to all premium features. Cancel anytime. If you use Fern for more than 4 months, Lifetime is the better deal.
Go to your iPhone Settings > Apple ID > Subscriptions > Fern Premium > Cancel. Your premium features will remain active until the end of your current billing period. You can also manage subscriptions from within the Fern app via Settings > Manage Subscription.
All purchases are processed by Apple. To request a refund, visit reportaproblem.apple.com and select the Fern purchase. Apple handles all refund decisions.
Fern requires iOS 17.0 or later. It works on both iPhone and iPad.
Email us at support@fernapp.com. We aim to respond within 24 hours.
Yes! We're actively developing Fern and plan to add features like customizable widgets, additional themes, localization in more languages, and more. We'll never compromise on privacy regardless of new features. Have a suggestion? Email us at support@fernapp.com.