# OTMON vs Nautical Calculator.

The clearest difference is in-app purchases: OTMON at none against Nautical Calculator.'s 1. OTMON also leads on update cadence (every 2 months vs every 6 months). Nautical Calculator.'s advantage is iOS requirement (13.0 vs 15.6). On price, ads and device support there is nothing between them.

Both are free to download. Nautical Calculator. sells 1 one-off in-app purchase. OTMON asks for nothing beyond the download.

OTMON ships an update every 2 months, Nautical Calculator. every 6 months. The most recent releases landed on October 1, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | OTMON | Nautical Calculator. |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 6 months |
| Size | 39 MB | 42 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ardiansyah Setiawan Suci](https://appshunter.io/developer/1827901000) | [Nanjibhai Gorasiya](https://appshunter.io/developer/1834066312) |

## What reviewers say

### OTMON

[App page](https://appshunter.io/ios/app/otmon/id6749614899)

**Features:** macOS Compatibility

**In-app purchases:** none


### Nautical Calculator.

[App page](https://appshunter.io/ios/app/nautical-calculator/id6755711720)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime premium | $12.99 | one-time |


## Frequently asked questions

### Is OTMON free?

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

### Is Nautical Calculator. free?

Nautical Calculator. is free to download, with in-app purchases available.

### Do OTMON or Nautical Calculator. have ads?

Neither OTMON nor Nautical Calculator. shows ads.

### Which is updated more often, OTMON or Nautical Calculator.?

OTMON ships an update every 2 months, and Nautical Calculator. every 6 months. Most recently, OTMON was updated on October 1, 2026 and Nautical Calculator. on October 13, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*