# WhenDo vs Senstream

The clearest difference is update cadence: WhenDo at monthly against Senstream's every 3 months. WhenDo also leads on iOS requirement (8.1 vs 17.6). Senstream's advantage is device support (4 vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

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

WhenDo ships an update monthly, Senstream every 3 months. The most recent releases landed on October 2, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | WhenDo | Senstream |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.3 (3 ratings)](https://appshunter.io/ios/app/senstream/id1297743398/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Monthly** | Every 3 months |
| Monetization | Free | Free |
| Size | 22 MB | 19 MB |
| Requires iOS | **8.1** | 17.6 |
| Devices | iPad | **iPhone, iPad, Mac, Vision Pro** |
| Age rating | 4+ | 4+ |
| Developer | [Shanghai Zhiwei Robotics Co Ltd](https://appshunter.io/developer/643548685) | [Senstream, Inc.](https://appshunter.io/developer/1297743397) |

## What reviewers say

### WhenDo

[App page](https://appshunter.io/ios/app/whendo/id1001086940)

This tool provides a graphical programming environment for learning Arduino. It simplifies coding by allowing users to drag and combine blocks to create programs. The app supports wireless downloads to compatible Arduino devices and utilizes a cloud server for compilation.

**Highlights:** Graphical programming with drag-and-drop blocks, Clear logic structure (When, Centre Node, Do blocks), Cloud server compilation, Wireless BLE downloads, Compatible with Bluetooth 4.0 Arduino chips

**Features:** macOS Compatibility

**In-app purchases:** none


### Senstream

[App page](https://appshunter.io/ios/app/senstream/id1297743398)

This app records physiological signal data from a wearable ring, capturing electrodermal activity, ECG, PPG, temperature, and motion. It connects to the cloud for powerful data analysis, enabling new types of research.

**Highlights:** Electrodermal activity (EDA/GSR) capture, ECG and PPG data recording, Temperature and motion sensing, Mobile and cloud data synchronization, BIOPAC integration

**In-app purchases:** none


## Frequently asked questions

### Is WhenDo free?

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

### Is Senstream free?

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

### Do WhenDo or Senstream have ads?

Neither WhenDo nor Senstream shows ads.

### Which is updated more often, WhenDo or Senstream?

WhenDo ships an update monthly, and Senstream every 3 months. Most recently, WhenDo was updated on October 2, 2026 and Senstream on October 6, 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.*