Shadow Yoga vs RHRSpark
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
RHRSpark
Visualize your resting heart rate directly on your Apple Watch face with customizable complications. Choose from various styles and time windows to see your heart rate trends at a glance. Understand how your data is calculated with full transparency.
- Resting heart rate on watch face
- Sparkline, gauge, or corner complications
- 10 watch face complications
- 4 time window options (8H, 24H, 7D, 30D)
- Two distinct data sources
- Full calculation transparency
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RHRSpark puts your resting heart rate on your Apple Watch face as a sparkline, a gauge, or a corner complication. WHAT YOU GET • Three free 24-hour complications: a sparkline, a gauge, and a corner • Seven Pro complications across 8-hour, 7-day, and 30-day windows • Recent sedentary heart rate and Apple's daily resting heart rate, each labeled • Calculation notes for every complication in the iPhone gallery TWO SOURCES, SHOWN CLEARLY The 8-hour and 24-hour views use heart-rate samples that HealthKit labels as sedentary. The 7-day and 30-day views use Apple's daily resting heart rate. When there is no recent sedentary sample, the big number shows Apple's latest resting heart rate and says so. Longer gaps stay visible instead of being filled in. BUILT FOR THE WATCH FACE Choose rectangular, circular, or corner complications. A short HR or RHR label tells you which source you are seeing and leaves the sparkline the room. The Apple Watch app works without the iPhone app and keeps a record of your daily values. The iPhone app adds older days whenever you open it. ONE-TIME PRO UNLOCK Download free and use the three 24-hour complications. Unlock all ten with a single one-time purchase. No subscription, account, ads, or telemetry. PAIR IT WITH HRVSPARK HRVSpark gives the same direct view of raw SDNN heart rate variability across useful time windows. HealthKit data stays on your devices and moves only between your iPhone and Apple Watch through Apple frameworks. RHRSpark may request a small configuration file from filamentlabs.io to show current product messages. That request contains no health data. RHRSpark 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: RHRSpark at Free against Shadow Yoga's $4.99. RHRSpark 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, ratings volume, 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
RHRSpark is free to download; Shadow Yoga costs $4.99 up front. RHRSpark 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 RHRSpark. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
Shadow Yoga ships an update every 11 months, RHRSpark weekly. The most recent releases landed on November 1, 2026 and October 31, 2026 respectively.
| Parameter | Shadow Yoga | RHRSpark |
|---|---|---|
| Price | $4.99 | Free — better |
| Rating | 5.0 (1 ratings) | 5.0 (1 ratings) |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 | 1 |
| Update frequency | Every 11 months | Weekly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free with in-app purchases — 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
RHRSpark
In-app purchases
Shadow Yoga
No in-app purchases
RHRSpark
- RHRSpark Pro$0.99
- Tip Jar$2.99









