# ErgData vs NK Logbook

The clearest difference is rating: ErgData at 4.7 against NK Logbook's 3.8. ErgData also leads on in-app purchases (none vs 4) and update cadence (fortnightly vs every 4 months). NK Logbook's advantage is review sentiment (63% vs 46%) and iOS requirement (13.0 vs 16.0). On price, ads and device support there is nothing between them.

Both are free to download. NK Logbook sells 4 in-app purchases, starting at $9.99 per month. ErgData asks for nothing beyond the download.

ErgData holds the better App Store score, 4.7 against 3.8. That said, the two scores are not equally well evidenced: ErgData has 5.9K ratings behind it against 12, so its average is the more settled of the two. Written reviews complicate that: 46% of ErgData's written reviews are positive against 63% of NK Logbook's, so the app with the better star average is not the one people write more warmly about.

ErgData ships an update fortnightly, NK Logbook every 4 months. The most recent releases landed on October 20, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | ErgData | NK Logbook |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (5.9K ratings)](https://appshunter.io/ios/app/ergdata/id561716382/reviews)** | [3.8 (12 ratings)](https://appshunter.io/ios/app/nk-logbook/id1392561808/reviews) |
| Number of ratings | **5.9K** | 12 |
| Positive reviews | 45.6% of reviews | **62.5% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 4 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 76 MB | 57 MB |
| Requires iOS | 16.0 | **13.0** |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Concept2, Inc.](https://appshunter.io/developer/446481798) | [Nielsen-Kellerman Co.](https://appshunter.io/developer/698732840) |

## What reviewers say

### ErgData

[App page](https://appshunter.io/ios/app/ergdata/id561716382)

This app acts as a personal training partner for Concept2 equipment. It allows users to set up custom workouts, view real-time stats, track progress, and sync data with online platforms. It also offers workout of the day challenges and detailed post-workout analysis.

**Highlights:** Custom workout setup, Real-time workout stats, Progress tracking, Sync with Concept2 Logbook, Workout of the Day, Post-workout analysis, Apple Watch compatibility

**Features:** Apple Watch app

**In-app purchases:** none

**What reviewers like**

- 🚀 Great app
- 👍 Excellent stats
- 👍 Easy to use
- 👍 Seamless sync with Concept2 logbook
- 👍 Customizable heart rate zones

**What reviewers complain about**

- 🐛 Connection issues with PM5
- 🐛 Unreliable heart rate monitoring
- 🐛 Sync issues with Apple Health
- 🐛 Crashes and data loss
- 🐛 Frequent disconnections

**Reported bugs**

- Workout data not saving
- Heart rate data freezing
- Disconnects during workouts
- Sync issues with Apple Health and Strava
- Login issues and frequent logouts

**Requested features**

- Add friend mode
- Integrate Apple Watch support
- Add manual workout entry
- Implement landscape mode for iPad
- Integrate pace calculator


### NK Logbook

[App page](https://appshunter.io/ios/app/nk-logbook/id1392561808)

This app pairs with compatible GPS devices to import, review, and analyze session data. It also streams live performance measurements for coaches and spectators, offering real-time insights into rowing performance and location.

**Highlights:** Import session data from compatible devices, Review and analyze boat metrics and stroke profile, Stream live performance measurements, Real-time location tracking for safety and spectator viewing, Team management for coaches and athletes, Compare live data from multiple boats

**Features:** macOS Compatibility, Apple Wallet, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Coach Subscription | $9.99 | per month |
| Monthly Team Subscription | $74.99 | per month |
| Annual Coach Subscription | $99.99 | per year |
| Team Yearly Subscription | $749.99 | per year |


## Frequently asked questions

### Is ErgData free?

ErgData is free to download, with no in-app purchases.

### Is NK Logbook free?

NK Logbook is free to download, with in-app purchases available.

### Which has better reviews, ErgData or NK Logbook?

ErgData is rated higher. ErgData averages 4.7 out of 5 from 5.9K ratings, while NK Logbook averages 3.8 from 12 ratings.

### Do ErgData or NK Logbook have ads?

Neither ErgData nor NK Logbook shows ads.

### Which is updated more often, ErgData or NK Logbook?

ErgData ships an update fortnightly, and NK Logbook every 4 months. Most recently, ErgData was updated on October 20, 2026 and NK Logbook on October 9, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*