# Watchlog Bluetooth vs Datum Link

Watchlog Bluetooth and Datum Link 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.

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

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 23, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Watchlog Bluetooth | Datum Link |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | Free | — |
| Size | 25 MB | 69 MB |
| Requires iOS | **13.0** | 14.2 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Hydrotechnik UK Test Engineering Ltd](https://appshunter.io/developer/1515531717) | [DATUM ELECTRONICS LTD](https://appshunter.io/developer/1368397156) |

## What reviewers say

### Watchlog Bluetooth

[App page](https://appshunter.io/ios/app/watchlog-bluetooth/id6479214506)

This application facilitates Bluetooth connections for data collection from specific sensors. It is designed to work seamlessly with Hydrotechnik sensors, enabling efficient data transfer and management.

**Highlights:** Bluetooth connectivity, Hydrotechnik sensor support, Data collection, Data management

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

**In-app purchases:** none


### Datum Link

[App page](https://appshunter.io/ios/app/datum-link/id6755107604)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Watchlog Bluetooth free?

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

### Is Datum Link free?

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

### Do Watchlog Bluetooth or Datum Link have ads?

Neither Watchlog Bluetooth nor Datum Link shows ads.

### Which is updated more often, Watchlog Bluetooth or Datum Link?

Watchlog Bluetooth ships an update every 2 months, and Datum Link every 2 months. Most recently, Watchlog Bluetooth was updated on September 23, 2026 and Datum Link 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.*