# Simple Unit Convert Pro vs Gallons to Liters

The clearest difference is price: Simple Unit Convert Pro at Free against Gallons to Liters's $1.99. Simple Unit Convert Pro also leads on ads (none vs shown) and update cadence (every 2 months vs every 12 months). Gallons to Liters's advantage is iOS requirement (13.0 vs 15.1). On in-app purchases and device support there is nothing between them.

Simple Unit Convert Pro is free to download; Gallons to Liters costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Simple Unit Convert Pro ships an update every 2 months, Gallons to Liters every 12 months. The most recent releases landed on November 4, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Simple Unit Convert Pro | Gallons to Liters |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | **[5.0 (5 ratings)](https://appshunter.io/ios/app/simple-unit-convert-pro/id6477877519/reviews)** | — |
| Number of ratings | **5** | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Every 2 months** | Every 12 months |
| Monetization | Free | — |
| Size | 27 MB | 20 MB |
| Requires iOS | 15.1 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Annika Gadman](https://appshunter.io/developer/1728509902) | [JanoGroup LLC](https://appshunter.io/developer/1781461557) |

## What reviewers say

### Simple Unit Convert Pro

[App page](https://appshunter.io/ios/app/simple-unit-convert-pro/id6477877519)

This utility app offers a comprehensive solution for converting various units of measurement. It simplifies daily tasks by providing precise conversions for temperature, speed, distance, weight, volume, and area. Streamline your needs with this user-friendly converter.

**Highlights:** Temperature conversion (Fahrenheit/Celsius), Speed conversion (mph/kph), Distance conversion (miles/kilometers), Weight conversion (lbs/oz/kg), Volume conversion (cups/ml/gallons), Area conversion (sq ft/sq m)

**Features:** macOS Compatibility

**In-app purchases:** none


### Gallons to Liters

[App page](https://appshunter.io/ios/app/gallons-to-liters/id6742208973)

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

**In-app purchases:** none


## Frequently asked questions

### Is Simple Unit Convert Pro free?

Simple Unit Convert Pro is free to download, with no in-app purchases.

### Is Gallons to Liters free?

Gallons to Liters costs $1.99, with no in-app purchases.

### Do Simple Unit Convert Pro or Gallons to Liters have ads?

Gallons to Liters shows ads; Simple Unit Convert Pro does not.

### Which is updated more often, Simple Unit Convert Pro or Gallons to Liters?

Simple Unit Convert Pro ships an update every 2 months, and Gallons to Liters every 12 months. Most recently, Simple Unit Convert Pro was updated on November 4, 2026 and Gallons to Liters on October 4, 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.*