Shiftrest vs Iris
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Shiftrest
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Sleep smarter, not longer. ShiftRest is built only for shift workers - nurses, paramedics, pilots, truckers, and anyone whose body fights their schedule. Most sleep apps assume a 9-to-5 life. ShiftRest doesn't. It uses your real shift roster and your personal chronotype to calculate the exact hours your body will rest best - even when you're working 7pm to 7am. HOW IT WORKS 1. Take a 60-second chronotype quiz 2. Connect your Calendar (or enter shifts manually) 3. ShiftRest tells you when to sleep, when to wake, and how rested you'll be BUILT FOR SHIFT WORK - Circadian Rhythm Engine - personalized sleep windows by chronotype, age, gender - Smart Shift Detection - auto-imports rosters from your calendar - Sleep Debt Tracker - see what you owe your body, track recovery - Shift Readiness Score - know if you're rested enough before clocking in - Sleep Sounds - white, pink, brown noise; rain, ocean, forest, fan - Wind-Down Reminders - smart notifications timed to your shift - Home Screen Widgets - next shift + sleep recommendation at a glance - Apple Health sync - sleep data flows seamlessly SHIFTREST PRO Calendar sync, full sound library, advanced widgets, and personalized insights. Weekly, monthly, and yearly plans. Cancel anytime. PRIVACY Your sleep data stays on your device. We don't sell, share, or upload it. Designed with input from sleep researchers. QUESTIONS? shiftrest.forvibe.app
Iris
This app offers comprehensive period and cycle tracking with advanced features like irregular cycle detection and personal insight generation. It prioritizes user privacy by keeping all data on the device, avoiding data sharing with advertisers. It also syncs with Apple Health and includes educational content on hormones.
- Period and cycle prediction
- Irregular cycle tracking
- Personalized insights and pattern detection
- LH strip and BBT logging
- Apple Health synchronization
- Contraceptive and postpartum modes
- Symptom and mood tracking
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Every feature free. No subscription. No data sharing. Ever. Most period apps charge $10-15/month and have been caught sharing your reproductive health data with advertisers. Iris keeps everything on your device — no server, no account, no telemetry. Your cycle data never leaves your phone. PERIOD & CYCLE TRACKING Log your period and Iris predicts your next one, fertile window, ovulation day, and PMS phase — all mapped out weeks in advance. Colour-coded calendar, day log, and smart reminders included. IRREGULAR CYCLE TRACKING Iris detects cycle variability from your data and switches to honest prediction ranges instead of single dates. No fertile window guessing for irregular users. Built for PCOS, perimenopause, and anyone whose body doesn't fit the textbook. PERSONAL INSIGHTS & PATTERN DETECTION Iris turns your daily logs into useful patterns. See which symptoms, moods, discharge types, activity and vitals appear most often in each cycle phase, then tap into any pattern for phase distribution, cycle-day timing, recent history and prediction notes. After enough history, Iris can help you spot recurring signals like fatigue, cramps, mood shifts or discharge changes before they appear — with insights calculated privately on your device. LH STRIP LOGGING Log your daily ovulation test result — Negative, Positive, or Peak. Iris immediately shifts your ovulation estimate to reflect your actual LH surge. Over time, Iris learns your personal luteal phase length and uses it to sharpen every future prediction — replacing the generic 14-day default with your actual biology. No other free app does this. BBT TRACKING Log your basal body temperature each morning and Iris calculates your personal coverline. When three consecutive readings rise above it, Iris marks a confirmed thermal shift — retrospective confirmation that ovulation occurred. Pair BBT with LH strips for the Symptothermal Method: the most accurate natural fertility awareness method, completely free. APPLE HEALTH SYNC Bidirectional sync with Apple Health. Iris reads your period history, BBT from connected thermometers, sleep, and weight. Period days, BBT, LH results, and cervical mucus data are written back to your Health dashboard. Iris data always wins — Apple Health only fills fields you haven't already logged. CONTRACEPTIVE & POSTPARTUM MODE On the pill, hormonal IUD, or copper IUD? Contraceptive Mode pauses ovulation predictions, labels bleeds as withdrawal bleeds, and adds a daily pill reminder. Just had a baby? Postpartum Mode pauses predictions while you recover, then resumes when you're ready. SYMPTOM & MOOD TRACKING Log mood, 14 symptoms (cramps, bloating, fatigue, acne, brain fog, hair shedding, and more), discharge type with fertility context, sleep, weight, and notes for any day. HORMONE EDUCATION Visualise estrogen, progesterone, FSH, and LH across your full cycle — mapped to your specific cycle length so the chart reflects your actual rhythm. PARTNER SHARING Invite a partner to follow your cycle — view-only, end-to-end encrypted, and completely free. PRIVATE BY DESIGN Your data stays on your iPhone. No servers. Optional iCloud sync goes to your own iCloud account — we never see it. No telemetry. No data-collection SDKs. 100% FREE — NO EXCEPTIONS No premium tier. No subscriptions. No paywalls. Every single feature — LH logging, BBT charting, irregular cycle detection, Apple Health sync, contraceptive mode, postpartum mode, and more — is completely free for everyone, forever. Download Iris. Your cycle is yours.
Screenshots
Verdict
The clearest difference is ads: Shiftrest at none against Iris's shown. On price, update cadence, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Shiftrest sells 3 in-app purchases, starting at $1.99 per 7 days and Iris sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
Shiftrest ships an update every 2 weeks, Iris weekly. The most recent releases landed on August 25, 2026 and August 19, 2026 respectively.
| Parameter | Shiftrest | Iris |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.0 (1 ratings) — better |
| Number of ratings | — | 1 — better |
| Update frequency | Every 2 weeks | Weekly — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone | iPhone, iPad — better |
| Requires iOS | 16.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 14 MB | 9 MB |
| Age rating | 4+ | 4+ |
| Developer | EMRE KEP | Arbaz Siddiqui |
In-app purchases
Shiftrest
- Weekly3 Days trial$1.997 Days
- Monthly$3.991 Month
- Yearly$24.991 Year
Iris
- Remove Ads$2.99





