# FCD vs CIDR

The clearest difference is in-app purchases: FCD at none against CIDR's 1. CIDR's advantage is update cadence (every 3 weeks vs every 7 months). On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. CIDR sells 1 one-off in-app purchase. FCD asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for FCD against 5.0 for CIDR. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

FCD ships an update every 7 months, CIDR every 3 weeks. The most recent releases landed on September 8, 2026 and June 30, 2026 respectively.

## The numbers

| Metric | FCD | CIDR |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/fcd-tr1-adapter-application/id1438537309/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/cidr/id1564239813/reviews) |
| Number of ratings | 1 | 1 |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 3 weeks** |
| Monetization | Free | Free |
| Size | 2 MB | 23 MB |
| Requires iOS | **14.4** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ross Morrison](https://appshunter.io/developer/1438537308) | [ao-system, Inc.](https://appshunter.io/developer/1338624340) |

## What reviewers say

### FCD

[App page](https://appshunter.io/ios/app/fcd-tr1-adapter-application/id1438537309)

This application calibrates engine gauges for turboprop aircraft using an iPad. It connects via Bluetooth to a specialized adapter plugged into the back of the gauges, allowing full control of calibration parameters and download of flight log data.

**Highlights:** iPad-based calibration, Bluetooth connectivity, Control calibration parameters, Download flight log data, Supports TR1 engine gauges

**Features:** macOS Compatibility

**In-app purchases:** none


### CIDR

[App page](https://appshunter.io/ios/app/cidr/id1564239813)

This utility calculates IP address ranges from an IP address and subnet mask. It supports IPv4 calculations, including prefix display, address range counts, and bit notation. Useful for quick CIDR notation checks and subnet mask conversions.

**Highlights:** IP address range calculation, Subnet mask to CIDR conversion, IPv4 prefix display, Number of address ranges, Bit notation display, Quick reference table

**Features:** macOS Compatibility

**In-app purchases (1)**

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


## Frequently asked questions

### Is FCD free?

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

### Is CIDR free?

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

### Which has better reviews, FCD or CIDR?

FCD and CIDR are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.

### Do FCD or CIDR have ads?

Neither FCD nor CIDR shows ads.

### Which is updated more often, FCD or CIDR?

FCD ships an update every 7 months, and CIDR every 3 weeks. Most recently, FCD was updated on September 8, 2026 and CIDR on June 30, 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.*