O3Z vs Stopwatch°
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
O3Z
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Via BLE technology (Bluetooth Low Energy), this app allows to connect and use the ozone generator O3Z-Tech to monitor the sanitisation and download the sanitisation report.
Stopwatch°
This app provides precise timekeeping with multiple stopwatches for simultaneous activity tracking. It offers a distraction-free full-screen mode and allows data export for analysis. Enjoy a reliable, ad-free, and subscription-free timing experience.
- Multiple stopwatches
- Simultaneous activity timing
- Full-screen mode
- Intuitive interface
- CSV data export
- Ad-free experience
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Stopwatch helps you time activities and record laps on iPhone and iPad. Use a single stopwatch or run several at once for sports, cooking, training, experiments, and everyday tasks. • Time multiple activities Run stopwatches independently or start and stop them together. • Keep your timers organized Name your stopwatches and group them into folders for different activities. • Record and compare laps Give laps descriptive names, review split and total times, and compare your fastest, slowest, and average laps. • Choose your view Switch between digital and analog displays, or use fullscreen mode for a larger clock. • Export your results Save stopwatch and lap data as CSV files to review in a spreadsheet or share with others. • Adjust the display Choose your preferred time precision and customize stopwatch controls to suit how you use the app. Terms of Service: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://stopwatchapp.carrd.co/
Screenshots
Verdict
The clearest difference is update cadence: Stopwatch° at every 9 days against O3Z's every 4 months. O3Z's advantage is iOS requirement (13.0 vs 17.0). On price, ads, in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.
O3Z ships an update every 4 months, Stopwatch° every 9 days. The most recent releases landed on September 13, 2026 and September 25, 2026 respectively.
| Parameter | O3Z | Stopwatch° |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.8 (286 ratings) — better |
| Positive reviews | — | 98.5% of reviews |
| Number of ratings | — | 286 — better |
| Update frequency | Every 4 months | Every 9 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 13.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 4 MB | 23 MB |
| Age rating | 4+ | 4+ |
| Developer | STEM s.r.l. | Kai Oelfke |
Bugs and requests
O3Z
Not enough reviews yet to summarise bugs or requests.
Stopwatch°
Reported bugs
1 issue- CSV export not working (produces empty email)
Requested features
14 requests- Periodically ask for rating after extended use
- Add feature to sum time lapsed in folders
- Add feature to show start and end time for each lap
- Move reset or delete all buttons to less accessible locations
- Make buttons larger for easier use while biking
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- Make it float on the Lock Screen
- Add dark mode option
- Add option for different font colors for fastest/slowest laps in export
- Add option to delete single laps by swiping left
- Make delete confirmation optional
- Full screen option
- Make available for Apple Watch
- Visibly running current lap time on Apple Watch
- Rename folders
In-app purchases
O3Z
No in-app purchases
Stopwatch°
No in-app purchases
