# CONVERT UNITS vs OP

The clearest difference is in-app purchases: OP at none against CONVERT UNITS's 2. OP also leads on ads (none vs shown) and iOS requirement (11.0 vs 15.0). CONVERT UNITS's advantage is update cadence (weekly vs every 7 months). On price and device support there is nothing between them.

Both are free to download. CONVERT UNITS sells 2 in-app purchases, starting at $0.99 per month. OP asks for nothing beyond the download.

CONVERT UNITS ships an update weekly, OP every 7 months. The most recent releases landed on November 1, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | CONVERT UNITS | OP |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (1.4K ratings)](https://appshunter.io/ios/app/convert-units/id1114969241/reviews)** | — |
| Number of ratings | **1.4K** | — |
| Positive reviews | 75.8% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Weekly** | Every 7 months |
| Monetization | Free with in-app purchases | — |
| Size | 22 MB | 13 MB |
| Requires iOS | 15.0 | **11.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Adysseus](https://appshunter.io/developer/447444997) | [Pantavanij co., Ltd](https://appshunter.io/developer/1306655998) |

## What reviewers say

### CONVERT UNITS

[App page](https://appshunter.io/ios/app/convert-units/id1114969241)

This app offers extensive unit and currency conversion capabilities, including offline access for saved rates. It features a user-friendly interface with customizable options and supports a wide range of categories for everyday and specialized needs.

**Highlights:** Offline conversion for saved rates, 160 currencies and 126 cryptocurrencies, 685 units across 72 categories, Customizable themes (Premium), Split View support for iPad, Dark and light appearance support

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove ads | $0.99 | per month |
| Remove ads | $19.99 | one-time |

**What reviewers like**

- 👍 Quick & easy to use
- 👍 Ease of use
- 👍 Simple and easy to use
- 👍 Well thought out and easy to use
- 👍 Excellent and very reliable

**What reviewers complain about**

- 🐛 Ads obstruct use
- 🐛 Subscription required to remove ads
- 🐛 Currency conversion not working

**Reported bugs**

- App got stuck, required uninstall/reinstall to fix
- Navigation issues, unable to get back to home page

**Requested features**

- Option to convert between functions (length to volume)
- Remember last conversion settings for each category


### OP

[App page](https://appshunter.io/ios/app/op-buysite/id1306655999)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is CONVERT UNITS free?

CONVERT UNITS is free to download, with in-app purchases available.

### Is OP free?

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

### Do CONVERT UNITS or OP have ads?

CONVERT UNITS shows ads; OP does not.

### Which is updated more often, CONVERT UNITS or OP?

CONVERT UNITS ships an update weekly, and OP every 7 months. Most recently, CONVERT UNITS was updated on November 1, 2026 and OP on October 26, 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.*