# TetraClock+ vs Penlight.

The clearest difference is update cadence: Penlight. at daily against TetraClock+'s every 5 days. Penlight. also leads on price ($1.99 vs $2.99). TetraClock+'s advantage is device support (4 vs 1) and iOS requirement (14.0 vs 16.0). On ads and in-app purchases there is nothing between them.

TetraClock+ costs $2.99 and Penlight. $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

TetraClock+ ships an update every 5 days, Penlight. daily. The most recent releases landed on October 7, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | TetraClock+ | Penlight. |
| --- | --- | --- |
| Price | $2.99 | **$1.99** |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/penlight/id6621271103/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 days | **Daily** |
| Monetization | — | Paid |
| Size | 6 MB | 1 MB |
| Requires iOS | **14.0** | 16.0 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Legal Prompt Inc.](https://appshunter.io/developer/1490746932) | [My Call Bag LLC](https://appshunter.io/developer/1243282862) |

## What reviewers say

### TetraClock+

[App page](https://appshunter.io/ios/app/tetraclock-plus-falling-block/id6505106046)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### Penlight.

[App page](https://appshunter.io/ios/app/penlight/id6621271103)

This app provides a digital penlight with adjustable brightness and a built-in ruler for quick measurements. It also features color inversion for different examination needs and easy calibration using a credit card.

**Highlights:** Adjustable digital penlight brightness, Credit card calibration for accuracy, Color inversion for light/dark modes, Metric and imperial ruler, Educational examination tool

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

**In-app purchases:** none


## Frequently asked questions

### Is TetraClock+ free?

TetraClock+ costs $2.99, with no in-app purchases.

### Is Penlight. free?

Penlight. costs $1.99, with no in-app purchases.

### Do TetraClock+ or Penlight. have ads?

Neither TetraClock+ nor Penlight. shows ads.

### Which is updated more often, TetraClock+ or Penlight.?

TetraClock+ ships an update every 5 days, and Penlight. daily. Most recently, TetraClock+ was updated on October 7, 2026 and Penlight. on October 25, 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.*