Comparison

NeuroMetric vs HRVSpark

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

NeuroMetric

Read full description

NeuroMetric – Reaction Time Training NeuroMetric is a simple and focused app designed to train your reaction time, concentration, and mental focus. Each training session lasts 180 seconds. During the session, the screen will change to green at random intervals. Your task is to tap the screen as quickly as possible when the signal appears. The challenge is not only speed, but maintaining full concentration for the entire session. This app is ideal for users who want to improve: - Reaction speed - Focus and sustained attention - Mental alertness under time pressure How it works - Press the (+) button to start a new training session - Tap to begin when the start screen appears - React instantly when the screen turns green - Stay focused for the full 180 seconds - Open Sessions to review recent trainings and track consistency NeuroMetrics keeps the experience minimal and distraction-free, allowing you to focus entirely on training your mind and reactions. Train regularly, stay sharp, and improve your response time with NeuroMetrics.

About

HRVSpark

Visualize your raw heart rate variability data directly on your Apple Watch face with a dynamic sparkline complication. Get immediate insights into your body's trends without opaque scores or labels. A companion iPhone app provides detailed views and guidance.

Highlights
  • Raw HRV sparkline complication
  • 8-hour free complication
  • 24/7, 7-day, 30-day Pro views
  • Circular gauge and corner complications
  • iPhone companion app
  • No interpretation layer
  • Complication-first design
Features
Read full description

HRVSpark puts your heart rate variability on your Apple Watch face as a sparkline, a gauge, or a corner complication. It shows the SDNN readings saved in Apple Health and nothing more. WHAT YOU GET • Three free 8-hour complications: a sparkline, a gauge, and a corner • Seven Pro complications across 24-hour, 7-day, and 30-day windows • Gaps left visible when your watch took no readings • An iPhone app with a live gallery of every complication and setup help JUST YOUR HRV HRVSpark shows your SDNN values across useful time windows without turning them into a readiness, stress, or recovery score. What they mean for your day is up to you. BUILT FOR THE WATCH FACE The complications are designed for quick checks on the wrist. Each gauge places a recent value between the low and high of its window. The Apple Watch app works without the iPhone app and keeps a record of your daily averages. The iPhone app adds older days whenever you open it. ONE-TIME PRO UNLOCK Download free and use the three 8-hour complications. Unlock all ten with a single one-time purchase. No subscription, account, ads, or telemetry. PAIR IT WITH RHRSPARK RHRSpark gives the same direct view of resting heart rate, with recent sedentary heart rate and Apple's daily resting heart rate. HealthKit data stays on your devices and moves only between your iPhone and Apple Watch through Apple frameworks. HRVSpark may request a small configuration file from filamentlabs.io to show current product messages. That request contains no health data. If you claim the supporter thank-you, HRVSpark sends Apple's signed record of your HRVSpark purchase to filamentlabs.io so each purchase receives one RHRSpark Pro code. That record contains no health data. HRVSpark is for informational purposes only. It does not provide medical advice or diagnose, treat, cure, or prevent any medical condition.

Screenshots

NeuroMetric4 screens
HRVSpark4 screens

Verdict

The call

The clearest difference is in-app purchases: NeuroMetric at none against HRVSpark's 2. NeuroMetric also leads on iOS requirement (15.6 vs 17.0). On price, update cadence, ads 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. HRVSpark sells 2 one-off in-app purchases. NeuroMetric asks for nothing beyond the download.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on October 28, 2026 and October 14, 2026 respectively.

Scorecard2 real differences · 8 level
NeuroMetric versus HRVSpark: the parameters behind the verdict, then further details
ParameterNeuroMetricHRVSpark
PriceFreeFree
Rating—5.0 (2 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—2 — better
Update frequencyWeeklyWeekly
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Freemium
DevicesiPhone, iPodiPhone, iPad, Apple Watch — better
Requires iOS15.6 — better17.0
Further details — not scored
Size37 MB6 MB
Age rating12+4+
DeveloperThatsMobile GmbHJoel Farthing

In-app purchases

None

NeuroMetric

No in-app purchases

2 purchases

HRVSpark

One-time2
  • HRVSpark Pro$0.99
  • HRVSpark Tip Jar$4.99

Questions

Is NeuroMetric free?
NeuroMetric is free to download, with no in-app purchases.
Is HRVSpark free?
HRVSpark is free to download, with in-app purchases available.
Do NeuroMetric or HRVSpark have ads?
Neither NeuroMetric nor HRVSpark shows ads.
Which is updated more often, NeuroMetric or HRVSpark?
NeuroMetric ships an update weekly, and HRVSpark weekly. Most recently, NeuroMetric was updated on October 28, 2026 and HRVSpark on October 14, 2026.

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