# UnitConverter byNSDev vs おたよりカレンダー

The clearest difference is review sentiment: おたよりカレンダー at 100% against UnitConverter byNSDev's 20%. おたよりカレンダー also leads on update cadence (every 3 days vs every 5 months). UnitConverter byNSDev's advantage is in-app purchases (none vs 2) and ads (none vs shown). On price there is nothing between them.

Both are free to download. おたよりカレンダー sells 2 one-off in-app purchases. UnitConverter byNSDev asks for nothing beyond the download.

UnitConverter byNSDev ships an update every 5 months, おたよりカレンダー every 3 days. The most recent releases landed on October 4, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | UnitConverter byNSDev | おたよりカレンダー |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 20.0% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 5 months | **Every 3 days** |
| Monetization | Free | — |
| Size | 4 MB | 6 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [NIHON SYSTEM DEVELOPER CORPORATION](https://appshunter.io/developer/1198103734) | [KUREHO](https://appshunter.io/developer/1884942706) |

## What reviewers say

### UnitConverter byNSDev

[App page](https://appshunter.io/ios/app/unitconverter-bynsdev/id1229121492)

This tool converts between 26 different types of units, displaying conversion rates and allowing you to specify decimal places. It supports a vast array of units across categories like length, mass, volume, and more.

**Highlights:** Converts 26 types of units, Displays conversion rates, Customizable decimal places, Supports numerous units in various categories, User-submitted unit requests

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

**In-app purchases:** none


### おたよりカレンダー

[App page](https://appshunter.io/ios/app/id6767889790)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $1.99 | one-time |
| Plus | $9.99 | one-time |


## Frequently asked questions

### Is UnitConverter byNSDev free?

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

### Is おたよりカレンダー free?

おたよりカレンダー is free to download, with in-app purchases available.

### Do UnitConverter byNSDev or おたよりカレンダー have ads?

おたよりカレンダー shows ads; UnitConverter byNSDev does not.

### Which is updated more often, UnitConverter byNSDev or おたよりカレンダー?

UnitConverter byNSDev ships an update every 5 months, and おたよりカレンダー every 3 days. Most recently, UnitConverter byNSDev was updated on October 4, 2026 and おたよりカレンダー on October 10, 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.*