SRM PM9 vs CT School
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SRM PM9
This app provides advanced power measurement for cyclists, offering high accuracy in various conditions. It features magnet-less cadence, left/right balance, and pedal smoothness analysis, connecting seamlessly with ANT+ and Bluetooth devices.
- Magnet-less cadence
- Left/Right balance measurement
- Pedal smoothness analysis
- Automatic temperature compensation
- ANT+ and Bluetooth LE connectivity
- Rechargeable battery
- Zwift compatible
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Our 9th generation Spider PowerMeter takes our proven formula and updates it with modern features. The result is a PowerMeter that is easier to use, even more accurate, better to repair and has improved connectivity. Thanks to a combination of angle and torque measurement, the PM9 is now able to measure with higher accuracy in very low cadence situations and not round chainrings do no longer have an impact on the recorded data. The integrated temperature sensor allows for maximum accuracy in changing conditions. Users are now able to show L&R balance, as well as combined Pedal smoothness. PowerMeter 9 comes with many usability improvements. First of all is the Magnet-less cadence mode, which allows you to use the PowerMeter without any cadence magnet. PowerMeter 9 can be used with ANT+ and Bluetooth LE. It connects to pretty much any head unit and comes with a mobile App. The App gives you access to live torque data, battery status information, firmware updates and much more. Features: • Magnet-less cadence • Left / Right Balance • Combined Pedal smoothness • Not round chainrings compatible • Automatic temperature compensation with sensor • Rechargeable via magnetic charger • 100 h battery runtime between charges • Compatible with Head-Units using ANT+™ and Bluetooth® • Zwift™ compatible
CT School
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Welcome to the CT School members app! Download our app to plan and book your fitness classes. At the click of a button, you can view class schedules, sign up for classes and even invite a friend to join you! With the app, you’ll keep in touch with CT School staff and coaches, receive notifications, news and reminders.
Screenshots
Verdict
SRM PM9 and CT School are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
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.
SRM PM9 ships an update every 2 months, CT School every 6 weeks. The most recent releases landed on October 10, 2026 and October 18, 2026 respectively.
| Parameter | SRM PM9 | CT School |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) — better | — |
| Number of ratings | 2 — better | — |
| Update frequency | Every 2 months | Every 6 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPod | iPhone, iPod |
| Requires iOS | 15.1 | 15.1 |
| Further details — not scored | ||
| Size | 26 MB | 32 MB |
| Age rating | 4+ | 4+ |
| Developer | Ulrich Schoberer | Arbox LTD |
In-app purchases
SRM PM9
No in-app purchases
CT School
No in-app purchases









