Fast Clock vs Otosan
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Fast Clock
This application simulates a fast clock for model railroads. It allows for custom logos and maps, and can synchronize with external systems like JMRI or use real-time.
- Model railroad fast clock simulation
- Custom logo support
- Custom map integration
- JMRI time synchronization
- Real-time clock option
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A model railroad fast clock app Supports custom logos Supports custom maps Can read time from JMRI, the built-in fast clock, or real time
Otosan
Generate any sound frequency between 20Hz and 20,000Hz for relaxation, meditation, or testing hearing. Includes a simple instrument tuner and bonus tracks.
- Adjustable frequency generator (20Hz-20,000Hz)
- Hearing range testing
- Instrument tuner
- Supports popular relaxation frequencies (432Hz, 528Hz)
- Includes bonus audio tracks
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Enter any value from 20Hz to 20,000Hz to play your favorite frequency, or use the slider to test your hearing range. Frequencies like 432Hz and 528Hz are popular for relaxation, meditation, yoga, studying, and sleep. The built-in tuner also works great for tuning instruments. Simple design with a retro feel. Includes 3 bonus tracks: RetroTone_A440.0Hz / RetroTone_A432.0Hz / RTSHealing_A432.0Hz.
Screenshots
Verdict
The clearest difference is review sentiment: Otosan at 100% against Fast Clock's 25%. Fast Clock's advantage is update cadence (every 2 days vs weekly) and iOS requirement (15.6 vs 26.2). On price, ads, in-app purchases and monetization model 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.
Fast Clock ships an update every 2 days, Otosan weekly. The most recent releases landed on November 3, 2026 and November 5, 2026 respectively.
| Parameter | Fast Clock | Otosan |
|---|---|---|
| Price | Free | Free |
| Rating | 3.8 (5 ratings) — better | — |
| Positive reviews | 25.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 5 — better | — |
| Update frequency | Every 2 days — better | Weekly |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 15.6 — better | 26.2 |
| Further details — not scored | ||
| Size | 5 MB | 102 MB |
| Age rating | 4+ | 4+ |
| Developer | Kevin Snow | HIROSHI SHINKAWA |
Customer experience
Fast Clock
Otosan
In-app purchases
Fast Clock
No in-app purchases
Otosan
No in-app purchases
