VoltLog vs RynDevice
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
VoltLog
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VoltLog is a field tool for FPV pilots who use LiPo, LiHV, and Li-ion battery packs without smart battery electronics. After a flight, log the pack voltage and VoltLog shows the safety status of each battery on a clear, color-coded dashboard. The goal is simple: know which packs are safe for storage, which need charging, and which should not be left full for too long. Built for FPV battery routines: - Track battery packs with name, brand, cell count, capacity, chemistry, and cycle count - Log voltage per cell with a large custom keypad - See STORAGE, CHARGED, FULL, FULL RISK, DISCHARGED, and CRITICAL states at a glance - Open full cycle history for every pack - Set global and per-battery alert timing - Use local notifications for risky full packs and low-voltage reminders - Work offline-first with local Drift storage - Secure or switch accounts with Supabase Auth when you want cloud-backed data VoltLog is not a charger, cell checker, or battery management system. It is a practical logbook for pilots who already measure voltage and want a faster way to keep track of many packs. Designed for the field, not a desk: - High-contrast dark dashboard - Large battery tiles - Fast voltage entry without the system keyboard - Battery archive for retired packs - English and Polish interface If your FPV case has more packs than memory can reliably track, VoltLog gives you one place to see what needs attention before battery degradation becomes expensive. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
RynDevice
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RynDevice shows you everything your iPhone can tell you about itself — clearly organized, honestly labeled, and readable offline. ■ 19 categories, every value in one place Device, System/OS, CPU, Graphics, Memory, Storage, Battery, Display, Camera, Network, Sensors, Location, Connectivity, Sound & Media, Security, Hardware features, Thermal — plus test tools and settings. ■ Live sensor graphs View readings from the accelerometer, gyroscope and other sensors in real time, with per-axis charts and full technical details. ■ 9 hardware tests Display, touch, speaker, microphone, camera, flashlight, vibration, GPS and sensors — pass/fail per test, with a shareable report. Handy when checking a used phone before buying or selling. ■ See where every value comes from Turn on “Value source” to see the exact iOS API behind each value (utsname.machine, ProcessInfo, …). Built for developers and QA. ■ Honest about limits When iOS doesn’t expose a value (serial number, IMEI, …), RynDevice says “Restricted” instead of guessing — never a made-up number. ■ Permissions only when needed Permissions are requested only on the screens that actually need them, with a clear reason — and you can decline and keep using everything else. ■ Works offline All device info and tests work without a network. ■ Light & dark, 5 languages A first-class dark mode, and full support for English, 한국어, 日本語, Deutsch and Português (Brasil). Your device data is read to be shown on screen. Exports leave the device only when you share them yourself. RynDevice shows ads (Google AdMob); ad-related data is described in the privacy policy: https://cs.devryner.com/apps/ryndevice/privacy
Screenshots
Verdict
The clearest difference is in-app purchases: RynDevice at none against VoltLog's 3. VoltLog's advantage is ads (none vs shown) and iOS requirement (16.0 vs 26.0). On price 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. VoltLog sells 3 in-app purchases, starting at $9.99 per month. RynDevice asks for nothing beyond the download.
| Parameter | VoltLog | RynDevice |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 10 days | — |
| Ads | No — better | Yes |
| In-app purchases | Yes | No — better |
| Devices | iPhone | iPhone |
| Requires iOS | 16.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 54 MB | 25 MB |
| Age rating | 4+ | 4+ |
| Developer | Filip Rusin | Chi Won Choi |
In-app purchases
VoltLog
- Monthly Pro$9.991 Month
- Yearly Pro$39.991 Year
- Lifetime Pro$99.99
RynDevice
No in-app purchases









