Krun vs Spinertia
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Krun
Engage with a digital pinwheel that creates captivating optical illusions as it spins and slows. Customize shapes, colors, and speed for a unique visual experience. It's a simple yet mesmerizing tool for all ages.
- Swipe-to-spin pinwheels
- Illusions appear as rotation slows
- Shape, color, and speed customization
- Unlock all content
- Remove ads
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Spin a pinwheel and watch hidden shapes appear while it's moving. Swipe to spin, then enjoy optical illusions as the speed changes. Simple and intuitive for kids and adults. • Swipe-to-spin pinwheels • Illusions that appear as rotation slows • Shape, color, and speed customization • Premium: unlock all and remove ads
Spinertia
Experience a realistic digital fidget spinner with responsive haptics and dynamic sound. Control your spins with flicks, track performance metrics, and enjoy a distraction-free Zen Mode. This app offers a private and offline experience.
- Realistic inertia and haptics
- Dynamic sound effects
- Motion control with iPhone movement
- Customizable spin settings
- Performance tracking (RPM, speed, time)
- Zen Mode for distraction-free play
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A fidget spinner, reimagined for iPhone. Flick the outer edge and feel Spinertia respond to every move. Realistic inertia, responsive haptics, and dynamic sound come together to make each spin feel satisfying — from a quick flick to a slow, natural stop. FEEL EVERY SPIN Haptics and sound respond as the spinner accelerates and slows, adding weight and texture to every movement. SPIN YOUR WAY • Flick the outer edge to spin • Hold the center for a steadier grip • Choose from Metal, Clear Blue, and Glow Green • Turn Sound, Haptics, and Motion on or off independently • Track RPM, top speed, and spin time • Enter Zen Mode for a distraction-free spin MOVE WITH YOUR iPHONE Turn on Motion and Spinertia responds naturally as you tilt and move your iPhone. SIMPLE AND PRIVATE No account. No ads. No analytics. No tracking. Spinertia works offline, with motion data processed directly on your device. Whether you want a quiet moment, something satisfying to fidget with, or simply the pleasure of a good spin — give it a flick.
Screenshots
Verdict
The clearest difference is rating: Spinertia at 5.0 against Krun's 3.0. Spinertia also leads on in-app purchases (none vs 1) and ads (none vs shown). Krun's advantage is update cadence (every 3 days vs every 6 days) and device support (3 vs 1). On price, ratings volume and iOS requirement 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. Krun sells 1 one-off in-app purchase. Spinertia asks for nothing beyond the download.
Spinertia holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 1 respectively.
Krun ships an update every 3 days, Spinertia every 6 days. Both last shipped on October 31, 2026.
| Parameter | Krun | Spinertia |
|---|---|---|
| Price | Free | Free |
| Rating | 3.0 (2 ratings) | 5.0 (1 ratings) — better |
| Number of ratings | 2 — better | 1 |
| Update frequency | Every 3 days — better | Every 6 days |
| Ads | Yes | No — better |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, Apple Watch — better | iPhone |
| Requires iOS | 16.6 | 16.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Shinichiro Eto | 一聪 张 |
Customer experience
Krun
Spinertia
In-app purchases
Krun
- Premium Unlock$2.99
Spinertia
No in-app purchases
