# DEC Opcodes vs Twaf

The clearest difference is in-app purchases: Twaf at none against DEC Opcodes's 1. Twaf also leads on update cadence (daily vs every 8 days) and iOS requirement (15.0 vs 18.0). On price, rating, ratings volume and ads there is nothing between them.

Both are free to download. DEC Opcodes sells 1 one-off in-app purchase. Twaf asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for DEC Opcodes against 5.0 for Twaf. Both are backed by a comparable volume of ratings — 3 and 2 respectively.

DEC Opcodes ships an update every 8 days, Twaf daily. Both last shipped on October 7, 2026.

## The numbers

| Metric | DEC Opcodes | Twaf |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (3 ratings)](https://appshunter.io/ios/app/dec-opcodes/id6760246055/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/twaf/id6802470764/reviews) |
| Number of ratings | **3** | 2 |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 8 days | **Daily** |
| Monetization | Free | Free |
| Size | 42 MB | 15 MB |
| Requires iOS | 18.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [John Kennedy](https://appshunter.io/developer/284943103) | [robel abraha](https://appshunter.io/developer/6802470766) |

## What reviewers say

### DEC Opcodes

[App page](https://appshunter.io/ios/app/dec-opcodes/id6760246055)

Explore the instruction sets of legendary DEC computers like the PDP and VAX. This app provides detailed information on each instruction, historical context, and interactive lessons. Discover the machines that shaped modern computing.

**Highlights:** Instruction set reference, Historical context and photos, System specifications, Interactive assembly lessons, Search and filtering, Customizable themes, Simple assembler

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Buy Me a Coffee | $0.99 | one-time |


### Twaf

[App page](https://appshunter.io/ios/app/twaf/id6802470764)

This app provides daily guidance for the Ge'ez calendar and Orthodox Tewahedo traditions. It automatically calculates fasting and feast days, offers a visual year wheel, and includes prayers, saint profiles, and scripture readings. It also features a church directory and wedding planning tools, all available offline.

**Highlights:** Automatic Ge'ez calendar calculations, Circular Year Wheel for fasts and feasts, Interactive candlelit prayers, Saint profiles linked to feast days, Fasting Guide and scripture references, Ethiopian and Eritrean church directory, Offline functionality

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

**In-app purchases:** none


## Frequently asked questions

### Is DEC Opcodes free?

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

### Is Twaf free?

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

### Which has better reviews, DEC Opcodes or Twaf?

DEC Opcodes and Twaf are both rated 5.0 out of 5 on the App Store, from 3 and 2 ratings respectively.

### Do DEC Opcodes or Twaf have ads?

Neither DEC Opcodes nor Twaf shows ads.

### Which is updated more often, DEC Opcodes or Twaf?

DEC Opcodes ships an update every 8 days, and Twaf daily. Most recently, DEC Opcodes was updated on October 7, 2026 and Twaf on October 7, 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.*