RustAcademy vs Opcodes
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RustAcademy
Learn Rust programming through focused, bite-sized lessons and daily challenges. Master core concepts, algorithms, and syntax with guided practice and code reading. Ideal for developers seeking a deeper understanding of Rust.
- Bite-sized Rust lessons
- Guided practice and code reading
- Daily recall challenges
- Structured algorithm track
- Code completion exercises
- Favorite module saving
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RustAcademy is a focused Rust learning companion for developers who want real understanding, one short session at a time. Instead of throwing you into long lectures, it turns core Rust concepts into clear lessons, guided practice, code reading, and daily recall. Start with the foundations, then move through ownership, borrowing, lifetimes, pattern matching, traits, generics, collections, error handling, macros, async thinking, and concurrency. Each topic helps you recognize how Rust works in actual code, not just memorize definitions. RustAcademy also includes a structured algorithm track built for Rust learners. Study binary search, sorting patterns, stacks, queues, heaps, priority queues, hashing, graph traversal, topological ordering, union-find, caching, and concurrency patterns through readable explanations and visual learning pages. The goal is simple: understand the idea, see the Rust shape, then practice until it sticks. The daily challenge gives you a fast way to keep momentum. Complete a missing Rust token, check your answer, review the solution, and return the next day with a stronger memory. These small exercises are ideal for busy learners who want steady progress without opening a full textbook. Practice screens reinforce syntax, standard library concepts, and common programming patterns. Code snippets are highlighted for readability, answer input is lightweight, and feedback is immediate. Favorite important algorithm modules, revisit tough sections, and keep your learning path organized. RustAcademy is made for beginners moving beyond tutorials, students preparing for technical interviews, self-taught developers filling gaps, and experienced engineers coming to Rust from languages like JavaScript, Python, Java, C++, Go, or Swift. If ownership rules, borrow checking, trait bounds, iterators, or lifetimes have ever felt confusing, this app gives you a calmer way to practice them. What you can do with RustAcademy: • Learn Rust fundamentals through organized topics • Practice ownership, borrowing, traits, generics, and error handling • Build confidence with code completion exercises • Take a fresh daily Rust challenge • Study algorithm patterns with Rust-centered explanations • Review stacks, queues, heaps, graphs, hashing, union-find, and LRU cache design • Save favorite modules for later review Rust rewards precision. RustAcademy helps you develop that precision by giving you repeated contact with the language in small, practical steps. Open a topic, solve a prompt, read a pattern, mark what matters, and keep going. Over time, the syntax becomes less intimidating, the compiler’s rules become more familiar, and the design behind Rust starts to feel natural. Whether your goal is systems programming, backend services, command-line tools, WebAssembly, embedded work, or interview prep, RustAcademy gives you a steady place to practice the skills that matter. Learn the rules. Read the code. Solve the challenge. Build the habit.
Opcodes
This app provides a comprehensive reference for retro CPU opcodes, including detailed descriptions, assembly examples, and historical context. It covers eighteen iconic processors and offers features like search, sorting, and filtering for easy exploration of historical computing information.
- Opcode reference for 18 iconic processors
- Detailed instruction descriptions
- Hex, octal, decimal values
- Flags affected, addressing modes, cycle counts
- Assembly code examples
- CPU history and pinout diagrams
- Simple assembler/disassembler
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Opcodes – The Retro CPU Reference The definitive opcode reference for the legendary processors that launched the personal computer revolution. Whether you're a retrocomputing enthusiast, a student of computer history, writing code for classic hardware, or just a big old nerd - the Opcodes app gives you everything you need. Eighteen iconic processors covered: Intel 4004 · Intel 8008 · Intel 8080 · Intel 8085 · Intel 8088 · Zilog Z80 · Motorola 6800 · Intel 8085 · Motorola 6809 · MOS 6502 · Signetics 2650 · RCA 1802 - SC/MP · Motorola 68000 · Intel 8086 · WDC 65816 · Texas Instruments TMS9900 · INMOS Transputer · ARM2 For every opcode: • Full description of what the instruction does. • Hex, octal, and decimal values. • Flags affected. • Addressing modes and cycle counts. • Assembly code examples - including loops, conditionals, and common patterns. More than just opcodes: • CPU history and historical context. • IC pinout diagrams. • Notable systems that used each CPU, with memory maps and other background information. • Chip variants and successors. • A silly card game(!) • Simple assembler / disassembler for many CPUs. Built for exploration: • Search for opcodes by name or category. • Sort by mnemonic, opcode byte, or category. • Filter by category, Quick Find with a colorful map. • Undocumented instructions clearly marked and optionally displayed. More than microprocessors: • Information on key support chips: video, sound, memory and more. Cool design: • Clean, readable layout optimised for quick reference. • Multiple colour themes. • Full "dark mode" support. Everything is included with absolutely no in-app purchase required. Recent additions: • Quiz game - test your CPU knowledge! • Share CPU cards - beautiful shareable images showing specs and history for any processor • External references - curated links to community resources for all 18 CPUs • "Opcodes display first" setting - choose whether selecting a CPU shows opcodes or info first • Chip-maker colour themes - Zilog, MOS Tech, and Motorola replace the old themes • Enhanced 6502 docs - JMP page boundary bug, BRK behaviour, and Read-Modify-Write quirks • Fixed Scratchpad hang when switching tabs
Screenshots
Verdict
The clearest difference is price: Opcodes at Free against RustAcademy's $5.99. Opcodes also leads on update cadence (every 8 days vs every 6 weeks). RustAcademy's advantage is in-app purchases (none vs 1) and iOS requirement (16.4 vs 18.0). On ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Opcodes is free to download; RustAcademy costs $5.99 up front. Opcodes sells 1 one-off in-app purchase. RustAcademy asks for nothing beyond the download.
RustAcademy ships an update every 6 weeks, Opcodes every 8 days. The most recent releases landed on October 20, 2026 and October 7, 2026 respectively.
| Parameter | RustAcademy | Opcodes |
|---|---|---|
| Price | $5.99 | Free — better |
| Rating | — | 4.8 (6 ratings) — better |
| Number of ratings | — | 6 — better |
| Update frequency | Every 6 weeks | Every 8 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 16.4 — better | 18.0 |
| Further details — not scored | ||
| Size | 54 MB | 58 MB |
| Age rating | 4+ | 4+ |
| Developer | SimTeCon GmbH | John Kennedy |
In-app purchases
RustAcademy
No in-app purchases
Opcodes
- Buy Me a Coffee$0.99









