# RFCReaderPlus vs Sub Cipher

The clearest difference is in-app purchases: Sub Cipher at none against RFCReaderPlus's 1. On price, review sentiment, update cadence and ads there is nothing between them.

Both are free to download. RFCReaderPlus sells 1 one-off in-app purchase. Sub Cipher asks for nothing beyond the download.

RFCReaderPlus ships an update every 3 months, Sub Cipher every 7 months. The most recent releases landed on September 29, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | RFCReaderPlus | Sub Cipher |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[3.8 (4 ratings)](https://appshunter.io/ios/app/sub-cipher/id1582898316/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 7 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 3 MB | 40 MB |
| Requires iOS | 17.0 | **16.6** |
| Devices | iPhone, iPad | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [飞 龙](https://appshunter.io/developer/965611281) | [Eduard Schwan](https://appshunter.io/developer/594336989) |

## What reviewers say

### RFCReaderPlus

[App page](https://appshunter.io/ios/app/rfcreaderplus/id1573574247)

Access and read technical internet standards documents offline. Features include searching, bookmarking, text formatting, and navigation aids for various document formats.

**Highlights:** List all RFC documents, Search RFC by keywords or number, Add RFCs to favorites, Text formatting and styling, Offline RFC reading, Support for PDF and HTML formats

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Functional Version | $1.99 | one-time |


### Sub Cipher

[App page](https://appshunter.io/ios/app/sub-cipher/id1582898316)

Easily encode and decode messages using simple substitution ciphers like Caesar and Atbash. Convert up to 2,000 characters at a time and save your cipher settings for later use. Ideal for fun educational purposes, not for serious secret messaging.

**Highlights:** Encode/decode simple substitution ciphers, Supports Caesar and Atbash cipher methods, Converts up to 2,000 characters at once, Save cipher settings as text, Create magic decoder wheels, No licensing or royalties required for published ciphers

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is RFCReaderPlus free?

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

### Is Sub Cipher free?

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

### Do RFCReaderPlus or Sub Cipher have ads?

Neither RFCReaderPlus nor Sub Cipher shows ads.

### Which is updated more often, RFCReaderPlus or Sub Cipher?

RFCReaderPlus ships an update every 3 months, and Sub Cipher every 7 months. Most recently, RFCReaderPlus was updated on September 29, 2026 and Sub Cipher on October 1, 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.*