# SensorLog — Log and Stream Sensor Data

> Log and stream sensor data from iOS devices and Apple Watch. (iPhone/iPad app by Bernd Thomas.)

- Source: https://appshunter.io/ios/app/sensorlog/id388014573 (this page in markdown: same URL + `.md`)
- Developer: [Bernd Thomas](https://appshunter.io/developer/385441510)
- Category: Utilities, Education
- Price: $2.99 with in-app purchases (on sale, was $5.99)
- Rating: 4.40/5 from 40 App Store ratings · 126 written reviews indexed
- Age rating: 4+
- Requires: iOS 18.0 · 4 MB
- Languages: German (Germany), American English
- Released: 2010-09-08
- Data updated: 2026-08-27
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/sensorlog/id388014573/reviews.md

## What is SensorLog?

With SensorLog you can read sensor data from the iPhone, iPad and Apple Watch.

The sensor data can be saved as a file in CSV or JSON format, streamed via TCP/UDP or sent as an HTTP request.

The most important functions for iPhone and iPad:

- Sensor data can be recorded at up to 100Hz (depending on the iOS device version and sensor type).
- Sensor data can be streamed in server or client mode using TCP or UDP. Depending on the network speed and the server or client configuration used, this is possible with up to 100Hz.
- Via HTTP(S) GET/POST request, sensor data in JSON format (POST) or form-url encoded (POST and GET) can be transmitted to a REST API with up to 20Hz.
- With the SensorLog Remote Client/Server function, an iPad or iPhone can connect as a SensorLog Remote Client to an iPhone or iPad, which takes on the role of SensorLog Remote Server. The client's sensor data can be visualized on the server, and the server can control the clients (start/stop logging, start/stop sending data).
- Logging can be started and stopped using Siri and shortcuts.
- SensorLog supports Core ML models created with Apple's Create ML app. Log data with SensorLog, train a model with the data in Create ML, load exported models in SensorLog and log the model prediction. Supported Create ML models are: Activity Classifier, Tabular Regressor and Tabular Classifier.
- If you have an Apple Watch, HealthKit data such as heart rate, energy used, sleep and movement data can be exported on the watch as a csv or json file and then transferred to your iPhone.

Sensor data iPhone / iPad:
For sample log files, please visit the SensorLog homepage (link App Support).
- CLLocation, CLHeading, CMAccelerometer, CMGyroData, CMMagnetometer, CMDeviceMotion, CMActivity, CMPedometer, CMAltimeter, WLAN and network provider IP addresses, device orientation, battery info, decibels.


The most important functions for Apple Watch:

- Logging Option 1: Logging duration up to 1 hour
Simultaneous logging of all selectable sensor data is supported in the background with up to 50Hz. Individual sensors can be logged with a higher frequency of up to 100Hz. Sending data via HTTP requests is supported.
- Logging option 2: Logging duration greater than 1 hour
In the background only logging of the accelerometer data with max. 50Hz is supported. In the foreground all sensor data with up to 100Hz. Sending data via HTTP requests is only supported when the app is in the foreground.
- Via HTTP(S) GET/POST request, sensor data can be transmitted to a REST API with up to 10Hz in JSON format (POST) or form-url encoded (POST and GET).
- The Health Store data feature off the SensorLog Watch app allows you to export HealthKit data like heart rate, energy burned, sleep, and movement data. This data is automatically recorded by your Watch and can be read out and exported by SensorLog as csv or json file and transferred to your iPhone.
- Logging can be started and stopped using Siri and Shortcuts.

Sensor Data Watch:
For sample log files, please visit the SensorLog homepage (link App Support).
- CLLocation, CMAccelerometer, CMDeviceMotion, CMActivity, CMPedometer, CMAltimeter, battery info

## Key features

- Log sensor data up to 100Hz
- Stream data via TCP/UDP or HTTP
- Export data as CSV or JSON
- Remote client/server functionality
- Siri and Shortcuts integration
- Core ML model support
- HealthKit data export from Apple Watch

## Pricing and in-app purchases

Base price: $2.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Buy me a Coffee ... | $0.99 | one-time |
| Spend me an Ice Cream ... | $1.99 | one-time |
| Offer me a glas of Wine ... | $5.99 | one-time |
| Invite me for a Cocktail ... | $9.99 | one-time |


## Recent user reviews (10 of 126)

All indexed reviews: https://appshunter.io/ios/app/sensorlog/id388014573/reviews.md

### 1/5 — Crashes on the watch

*2026-05-17, version 6.1*

As soon as I start recording on the watch the watch app crashes.  This is my use case, so 1 star.

### 5/5 — Great

*2026-03-25, version 6.1*

I have used this app to record motion data many times over the years and it still works well.

### 1/5 — Flushing buffer

*2026-02-20*

Can you update the app to stop flushing buffer all the time!? I want to record sensor data every 10 secs. After a while, it keeps flushing buffer! I have to wait it to be okay, wasting quite a lot of time!

### 5/5 — WELL DONE!

*2025-08-12, version 6.1*

this powerful app is easy to use and does what is advertised.

### 5/5 — hello

*2025-07-02*

姿态角的单位是否可以选择度数而不是弧度 至少增加一个开关做切换

### 5/5 — Deutsch

*2024-11-28, version 6.1*

Das Programm ist sehr gut, aber wie kann man es auf Deutsch einstellen. Als Sprachen werden Englisch und Deutsch angegeben. 
Vielen Dank!

### 2/5 — Looks good but

*2024-10-31, version 5.3.1*

Doesn’t log anything on Apple Watch

### 5/5 — Amazing free app, more features than even paid apps.

*2024-08-23, version 5.3.1*

I was looking for an app that could steam device accelerometer data across the network to my PC. This app offers that and more, all for free.

### 5/5 — The most comprehensive tracking app I have seen

*2024-06-11, version 5.3.1*

This application offers precise location recording on iOS, with a precision that is unmatched by all the other options I have tried.

Moreover, it lets you record all sorts of other parameters, like sound levels, orientation, battery level, steps counting, and more. It also exposes raw sensor data like magnetic and gyroscopic measurements.

The app is very customizable: you can set the recorded parameters, the sampling rate, and various output methods. All of this while integrating nicely with the OS.

The developer is helpful and quickly solved the few issues I was having with the app.

Definitely recommended.

### 5/5 — Amazing

*2024-02-03, version 5.3.1*

This is what software is supposed to be. It works, it’s simple, it’s to the point, and it had a simple, no tricks pay once structure. After coming up with a project a couple years ago I finally implemented a POC of integrating sensor logs with an esp32 mesh network controlled by orange pi 5 plus. Works great, incredibly simple since all the hard work of the server setup is done. What’s better is how easy the config process is. Literally all the things you want on one screen. Bonus for downloadable configs!

Apps like this are why I’ve started making more of my own apps/projects. It’s hard to argue with special purpose no frills or trying to sell regurgitated poorly modified open source software (how many camera apps does one need to pay for that all utilize the same underlying software….poorly?). This is true software. Made by someone for a purpose which wasn’t to “get rich” quick selling bad derivatives. 

Bravo. 👍

## Frequently asked questions about SensorLog

### What kind of sensor data can this app log?

The app can log a wide range of sensor data from iPhones and iPads, including location, heading, accelerometer, gyroscope, magnetometer, device motion, activity, pedometer, altimeter, Wi-Fi information, IP addresses, device orientation, and battery status. For Apple Watch, it can log accelerometer data, and also export HealthKit data like heart rate, energy used, sleep, and movement.

### How can I export or share the logged sensor data?

Logged sensor data can be saved as a file in CSV or JSON format. Additionally, the data can be streamed in real-time via TCP/UDP or sent as an HTTP request to a REST API. This allows for flexible integration with other systems and analysis tools.

### Is this app free to use?

The application is free to download and use, but it offers in-app purchases. These purchases likely unlock advanced features or remove limitations, providing a freemium model for users.

### What devices is SensorLog compatible with?

SensorLog is designed to work with iPhones, iPads, and Apple Watches. The specific sensor data available and logging capabilities may vary slightly depending on the iOS device version and the specific sensor type.

### Can I use this app for machine learning projects?

Yes, the app supports Core ML models created with Apple's Create ML app. You can log data with SensorLog, train a model using that data, and then load the exported models back into SensorLog to log model predictions. This is particularly useful for Activity Classifier, Tabular Regressor, and Tabular Classifier models.

## Version history (last 5 releases)

### 6.1 — 2024-11-05

bugfix resolving app crash

### 6.0 — 2024-11-03

bugfixes
watch: 
- standalone version of watch App
- upload of log files via HTTPS

### 5.3.1 — 2023-03-15

- bug fixes

iPhone/iPad:
- SensorLog configuration files. Support for saving, and loading SensorLog configuration files. Downloading of configuration settings from Web server via HTTP.
- SensorLog Remote client supports incoming JSON requests:
 {"request":"status"}
 {"request":"startLogging"}
 {"request":"stopLogging"}
 {"request":"startSendingSensorData"}
 {"request":"stopSendingSensorData"}
 {"request":"setDataLabel", "label":0..5}

- SensorLog Remote server supports incoming JSON requests:
  {"request":"status"}
  {"request":"startLogging"}
  {"request":"stopLogging"}
  {"request":"setDataLabel", "label":0..5}
  {"request":"startLoggingAllConnectedClients"}
  {"request":"stopLoggingAllConnectedClients"}
  {"request":"loadConfiguration", "url":"URL_SENSORLOG_CONFIG_FILE"}
  {"request":"setDataLabelAllConnectedClients", "label":0..5}

- SensorLogRemote server can now be started with dedicated server port
- Beta status: Support for connecting at most one external Bluetooth sensor/device to log its data into a separate log file or to merge its data with the builtin sensors' log file/stream/http. Please note this is still in a beta status.
- added configuration option to "auto set initial attitude reference" before starting to log data.
- added support to start SensorLog with a specific configuration via custom app link by using the link SensorLog://configure/?urlConfigurationServer=URL. You can set the URL and it will automatically fetch the JSON configuration file from the server.

Watch:
- Unfortunately had to remove tcp/ip streaming and Remote Sensorlog feature, due to changes in the low level networking functions of watchOS.
- SensorLog configuration files. Support for saving, and loading SensorLog configuration files. Downloading of configuration settings from Web server via HTTP.
- added configuration option to "auto set initial attitude reference" before starting to log data.
- added HealthKit Export of envAudioExposure data

### 5.3 — 2023-03-13

iPhone/iPad:
- SensorLog configuration files. Support for saving, and loading SensorLog configuration files. Downloading of configuration settings from Web server via HTTP.
- SensorLog Remote client supports incoming JSON requests:
 {"request":"status"}
 {"request":"startLogging"}
 {"request":"stopLogging"}
 {"request":"startSendingSensorData"}
 {"request":"stopSendingSensorData"}
 {"request":"setDataLabel", "label":0..5}

- SensorLog Remote server supports incoming JSON requests:
  {"request":"status"}
  {"request":"startLogging"}
  {"request":"stopLogging"}
  {"request":"setDataLabel", "label":0..5}
  {"request":"startLoggingAllConnectedClients"}
  {"request":"stopLoggingAllConnectedClients"}
  {"request":"loadConfiguration", "url":"URL_SENSORLOG_CONFIG_FILE"}
  {"request":"setDataLabelAllConnectedClients", "label":0..5}

- SensorLogRemote server can now be started with dedicated server port
- Beta status: Support for connecting at most one external Bluetooth sensor/device to log its data into a separate log file or to merge its data with the builtin sensors' log file/stream/http. Please note this is still in a beta status.
- added configuration option to "auto set initial attitude reference" before starting to log data.
- added support to start SensorLog with a specific configuration via custom app link by using the link SensorLog://configure/?urlConfigurationServer=URL. You can set the URL and it will automatically fetch the JSON configuration file from the server.

Watch:
- Unfortunately had to remove tcp/ip streaming and Remote Sensorlog feature, due to changes in the low level networking functions of watchOS.
- SensorLog configuration files. Support for saving, and loading SensorLog configuration files. Downloading of configuration settings from Web server via HTTP.
- added configuration option to "auto set initial attitude reference" before starting to log data.
- added HealthKit Export of envAudioExposure data

### 5.2 — 2022-03-04

iPhone / iPad
- bugfix: crash long term acceleromter export view
- SensorLog Remote server mode now supports logging of sensor data from connected SensorLog Remote clients

## Apps similar to SensorLog

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Sensor-App](https://appshunter.io/ios/app/sensor-app/id1466399692) | 4.0 (4) | Free | Utilities |
| [Watch Sensor Logger](https://appshunter.io/ios/app/watch-sensor-logger/id1634449655) | — | Free | Utilities |
| [Sensor Play - Data Recorder](https://appshunter.io/ios/app/sensor-play-data-recorder/id921385514) | 4.7 (59) | $14.99 | Utilities |
| [Sensors Toolbox](https://appshunter.io/ios/app/sensors-toolbox/id1242203428) | 4.7 (160) | Free | Utilities |
| [Accelerometer – G-Force Meter](https://appshunter.io/ios/app/accelerometer-g-force-meter/id499629589) | 4.0 (1) | Free | Utilities |
| [Sensors Toolbox - Multitool](https://appshunter.io/ios/app/sensors-toolbox-multitool/id1383687190) | 4.2 (134) | Free | Utilities |

## Related topics

[sensorstream](https://appshunter.io/ios/topics/sensorstream)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-27.*