Comparison

SRM PM9 vs CT School

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • Magnet-less cadence
  • Left/Right balance measurement
  • Pedal smoothness analysis
  • Automatic temperature compensation
  • ANT+ and Bluetooth LE connectivity
  • Rechargeable battery
  • Zwift compatible
Features
Read full description

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

About

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

SRM PM94 screens
CT School4 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

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.

ScorecardNo meaningful differences
SRM PM9 versus CT School: the parameters behind the verdict, then further details
ParameterSRM PM9CT School
PriceFreeFree
Rating5.0 (2 ratings) — better—
Number of ratings2 — better—
Update frequencyEvery 2 monthsEvery 6 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPodiPhone, iPod
Requires iOS15.115.1
Further details — not scored
Size26 MB32 MB
Age rating4+4+
DeveloperUlrich SchobererArbox LTD

In-app purchases

None

SRM PM9

No in-app purchases

None

CT School

No in-app purchases

Questions

Is SRM PM9 free?
SRM PM9 is free to download, with no in-app purchases.
Is CT School free?
CT School is free to download, with no in-app purchases.
Do SRM PM9 or CT School have ads?
Neither SRM PM9 nor CT School shows ads.
Which is updated more often, SRM PM9 or CT School?
SRM PM9 ships an update every 2 months, and CT School every 6 weeks. Most recently, SRM PM9 was updated on October 10, 2026 and CT School on October 18, 2026.

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