# Sensor Switch VLP vs Klein Borescope ET21

The clearest difference is ads: Klein Borescope ET21 at none against Sensor Switch VLP's shown. Klein Borescope ET21 also leads on rating (2.2 vs 1.8) and monetization model (free vs ad-supported). On price, ratings volume, in-app purchases and device support there is nothing between them.

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

Klein Borescope ET21 holds the better App Store score, 2.2 against 1.8. Both are backed by a comparable volume of ratings — 26 and 9 respectively.

Sensor Switch VLP ships an update every 5 months, Klein Borescope ET21 every 2 months. The most recent releases landed on October 27, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Sensor Switch VLP | Klein Borescope ET21 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.8 (26 ratings)](https://appshunter.io/ios/app/sensor-switch-vlp/id1251644551/reviews) | **[2.2 (9 ratings)](https://appshunter.io/ios/app/klein-borescope-et21/id6740300461/reviews)** |
| Number of ratings | **26** | 9 |
| Positive reviews | 25.0% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | Ad-supported | **Free** |
| Size | 116 MB | 19 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Acuity Brands Lighting, Inc](https://appshunter.io/developer/384447835) | [Klein Tools](https://appshunter.io/developer/440692921) |

## What reviewers say

### Sensor Switch VLP

[App page](https://appshunter.io/ios/app/sensor-switch-vlp/id1251644551)

This app allows for the visual configuration of occupancy sensors and photocontrols using flash programming technology. Users can easily adjust settings like time delay, trim values, and photocontrol options. It also offers Bluetooth connectivity for select sensors and includes security features.

**Highlights:** Visual sensor selection, Adjust occupancy time delay, Configure photocontrol options, Save sensor setting profiles, PIN code security, Bluetooth configurability

**Features:** macOS Compatibility

**In-app purchases:** none


### Klein Borescope ET21

[App page](https://appshunter.io/ios/app/klein-borescope-et21/id6740300461)

This app allows construction workers to capture pictures and videos of worksite progress and details using a WiFi borescope. It facilitates easy documentation of on-site conditions and project advancements.

**Highlights:** Picture capture, Video recording, WiFi connectivity, Worksite documentation, Progress tracking

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Sensor Switch VLP free?

Sensor Switch VLP is free to download, with no in-app purchases.

### Is Klein Borescope ET21 free?

Klein Borescope ET21 is free to download, with no in-app purchases.

### Which has better reviews, Sensor Switch VLP or Klein Borescope ET21?

Klein Borescope ET21 is rated higher. Sensor Switch VLP averages 1.8 out of 5 from 26 ratings, while Klein Borescope ET21 averages 2.2 from 9 ratings.

### Do Sensor Switch VLP or Klein Borescope ET21 have ads?

Sensor Switch VLP shows ads; Klein Borescope ET21 does not.

### Which is updated more often, Sensor Switch VLP or Klein Borescope ET21?

Sensor Switch VLP ships an update every 5 months, and Klein Borescope ET21 every 2 months. Most recently, Sensor Switch VLP was updated on October 27, 2026 and Klein Borescope ET21 on October 28, 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.*