Shadow Yoga vs HRVSpark
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Shadow Yoga
Learn the Shadow Yoga Preludes with animated demonstrations of Caranas and all three sequences. This app provides instructions to deepen your understanding of the practice, complementing in-person guidance from certified teachers.
- Animated Caranas
- All three Preludes demonstrated
- Instructional support
- Complements teacher instruction
- Supports understanding of practice
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The Shadow Yoga app is an aid designed to help in learning the Shadow Yoga Preludes. The app contains animations of the Caranas and all three Preludes. Instructions are also included that will support the student’s understanding of the practice. This app is intended to complement direct instruction from one of the teachers qualified to teach this subject listed on the Shadow yoga website. www.shadowyoga.com
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.
- 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
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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
Verdict
The clearest difference is price: HRVSpark at Free against Shadow Yoga's $4.99. HRVSpark also leads on update cadence (weekly vs every 11 months). Shadow Yoga's advantage is in-app purchases (none vs 2) and iOS requirement (12.0 vs 17.0). On rating, review sentiment, ratings volume and ads 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
HRVSpark is free to download; Shadow Yoga costs $4.99 up front. HRVSpark sells 2 one-off in-app purchases. Shadow Yoga asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 5.0 for Shadow Yoga against 5.0 for HRVSpark. Both are backed by a comparable volume of ratings — 1 and 2 respectively. Written reviews split almost evenly too, at 100% and 100% positive.
Shadow Yoga ships an update every 11 months, HRVSpark weekly. The most recent releases landed on November 1, 2026 and October 31, 2026 respectively.
| Parameter | Shadow Yoga | HRVSpark |
|---|---|---|
| Price | $4.99 | Free — better |
| Rating | 5.0 (1 ratings) | 5.0 (2 ratings) |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 1 | 2 — better |
| Update frequency | Every 11 months | Weekly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Freemium — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Requires iOS | 12.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 21 MB | 6 MB |
| Age rating | 4+ | 4+ |
| Developer | Shadow Yoga | Joel Farthing |
Customer experience
Shadow Yoga
HRVSpark
In-app purchases
Shadow Yoga
No in-app purchases
HRVSpark
- HRVSpark Pro$0.99
- HRVSpark Tip Jar$4.99









