# Units Free vs LIN Authenticator

The clearest difference is in-app purchases: LIN Authenticator at none against Units Free's 1. Units Free's advantage is update cadence (every 5 months vs every 12 months) and iOS requirement (5.1.1 vs 15.6). On price, ads and device support there is nothing between them.

Both are free to download. Units Free sells 1 one-off in-app purchase. LIN Authenticator asks for nothing beyond the download.

Units Free ships an update every 5 months, LIN Authenticator every 12 months. The most recent releases landed on August 15, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Units Free | LIN Authenticator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/units-free/id510615778/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 5 months** | Every 12 months |
| Monetization | Free with in-app purchases | — |
| Size | 3 MB | 31 MB |
| Requires iOS | **5.1.1** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Piet Jonas](https://appshunter.io/developer/288060167) | [NetKnights GmbH](https://appshunter.io/developer/1445401030) |

## What reviewers say

### Units Free

[App page](https://appshunter.io/ios/app/units-free/id510615778)

Easily convert between various units across multiple categories like length, temperature, and weight. Access past conversions through a history list and send calculations via email. This free version offers core functionality with an option to upgrade for full category access.

**Highlights:** Multiple unit categories (length, temp, weight, etc.), Metric and imperial system support, Conversion history list, Send calculations via email, iPad multitasking support

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Units Free Upgrade | $0.99 | one-time |


### LIN Authenticator

[App page](https://appshunter.io/ios/app/lin-authenticator/id6670431207)

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

**In-app purchases:** none


## Frequently asked questions

### Is Units Free free?

Units Free is free to download, with in-app purchases available.

### Is LIN Authenticator free?

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

### Do Units Free or LIN Authenticator have ads?

Neither Units Free nor LIN Authenticator shows ads.

### Which is updated more often, Units Free or LIN Authenticator?

Units Free ships an update every 5 months, and LIN Authenticator every 12 months. Most recently, Units Free was updated on August 15, 2026 and LIN Authenticator on September 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.*