Undercurrent vs NailPause
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Undercurrent
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You know something is off, but what? Headaches that seem random. Energy that crashes for no reason. You suspect a pattern, but every time the doctor asks "have you noticed any patterns?" you draw a blank. Undercurrent is a private notebook for the small things, and the patterns hiding inside them. LOG IN FOUR TAPS OR FEWER Symptoms, food, medications, activities, and observations. Quick chips for what you log most. Or just tell the on-device AI assistant in plain language: "headache after lunch" and it handles the rest. WHAT WE'VE NOTICED Once you've logged a few events, the Insights page surfaces co-occurrences in your own data, phrased in soft language. None of it claims to cause anything. You decide if it's signal or noise. • Pre-window pattern: what tends to show up in the hours before symptoms • Time-of-day cluster: when symptoms tend to gather • Day-of-week peak: which days run hottest • Recurring sequence: a familiar arc, repeated • Co-occurrence: tags that appear alongside symptoms • Seasonality: a year, at a glance (Pro) • Environment: weather, pressure, humidity, air quality (Pro) • Long-term cycles and intervention effectiveness (Pro) A REPORT YOU CAN HAND TO YOUR CLINICIAN (Pro) One tap exports an editorial PDF: auto-numbered observations, frequency tables, time-of-day distributions, and an event log. Black-and-white printable, sized for a five-minute appointment. No portal login on the other end. APPLE HEALTH INTEGRATION (Pro) Pull in workouts and mindful sessions automatically. The data stays on your device and is folded into the same patterns engine. TRACK MULTIPLE PEOPLE (Pro) Separate threads for yourself, your kids, or anyone you care for. Each thread gets its own timeline, observations, and reports. 100% PRIVATE BY DEFAULT • No account required, start logging immediately • All data stored locally on your device • AI runs on-device using Apple Intelligence; nothing is sent to a server to be analysed • Optional iCloud backup, protected by Apple's encryption • No analytics, no tracking, no ads BUILT ON PUBLISHED RESEARCH Self-monitoring is the most effective technique in digital health interventions for chronic conditions, backed by analysis of 85 clinical studies. Smartphone diaries have been shown to identify real triggers; visual diary summaries help patients and providers focus on actionable plans. FREE FOREVER • Unlimited logging of symptoms, food, meds, actions, observations • Today, Timeline, and Calendar views • AI chat assistant for plain-language logging • Basic Insights: pre-window, time-of-day, day-of-week, sequences, co-occurrences • Local-only data, stays on your device UNDERCURRENT PRO · ONE-TIME PURCHASE · $19.99 Pay once, keep everything forever. No subscription, no recurring charges. • Weather, pressure, and humidity correlations • Long-term cycles, seasonality, intervention effectiveness • Editorial PDF report for your clinician with full observation set • Track multiple people, with separate threads for each • Apple Health sync • iCloud backup Whether you're trying to figure out what shows up before your migraines, why your energy crashes after lunch, which foods leave you uncomfortable, or what helps your child sleep better, Undercurrent gives you a quiet place to write it down and the patterns that emerge over time. NOT A MEDICAL DEVICE Undercurrent describes statistical co-occurrences in your self-logged data. It is not intended to diagnose, treat, cure, or prevent any disease. Observations are informational only, not medical advice. Always consult a qualified healthcare professional about symptoms, medications, or treatment decisions. In an emergency, call your local emergency number. Notice what's quietly shaping how you feel.
NailPause
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Catch the urge before the bite. NailPause gives you a private 60-second reset when nail biting or cuticle picking starts to feel automatic. Notice the urge, choose a practical response, and make gradual recovery visible—without shame or all-or-nothing pressure. RESPOND IN THE MOMENT • Start a 60-second reset from the app, Home Screen, or Lock Screen • Choose a practical hands-on response • Note the trigger and urge intensity • Keep core resets unlimited on the free plan FOLLOW A PLAN BUILT AROUND YOU Tell NailPause what matters to you, when urges are most likely, and which response feels realistic. Your first 7-day plan turns those answers into small daily actions. Pro continues the complete 28-day guided Journey and adapts your next week using your real check-ins. UNDERSTAND YOUR PATTERNS See when urges are most likely, which triggers keep returning, and which responses help most. NailPause creates simple insights only from the information you choose to record. MAKE NAIL RECOVERY VISIBLE Take consistent nail and cuticle photos, compare progress side by side, and create a private on-device timelapse with Pro. Your recovery photos are not uploaded. FREE INCLUDES • Unlimited instant resets • Daily reflection and reminders • Care plant and Care Points • The first 7 Journey days • Up to 2 recovery photos • A 7-day reflection summary • Home Screen and Lock Screen widgets NAILPAUSE PRO ADDS • The complete 28-day Journey • 30 days of reflection history • Highest-risk-window and recurring-trigger insights • Trigger-aware reset recommendations • All five reset techniques • Weekly adaptive guidance • More recovery photos • Side-by-side comparison and an on-device timelapse PRIVATE BY DESIGN No account is required. Your plan, check-ins, notes, and recovery photos stay on your device. NailPause has no advertising or cross-app tracking. NailPause is a self-help and educational tool. It does not diagnose, treat, or replace care from a qualified health professional. Take the first pause today. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is update cadence: NailPause at weekly against Undercurrent's every 2 weeks. Undercurrent's advantage is iOS requirement (15.1 vs 17.0). On price, ads, 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. Undercurrent sells 1 one-off in-app purchase and NailPause sells 3 in-app purchases, starting at $7.99 per month. Whichever you choose, the download price is not the number that matters.
Undercurrent ships an update every 2 weeks, NailPause weekly. The most recent releases landed on September 19, 2026 and September 30, 2026 respectively.
| Parameter | Undercurrent | NailPause |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 2 weeks | Weekly — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 15.1 — better | 17.0 |
| Further details — not scored | ||
| Size | 69 MB | 16 MB |
| Age rating | 12+ | 4+ |
| Developer | Lloyd Rowat | NIYAZI ONER |
In-app purchases
Undercurrent
- Undercurrent Health: Pro$19.99
NailPause
- NailPause Pro Monthly$7.991 Month
- NailPause Pro Annual7 Days trial$29.991 Year
- NailPause Pro Lifetime$59.99









