# ROJIRAKU: Logic Gate Puzzle — Wire up gates, build a CPU > Wire up gates, build a CPU (iPhone/iPad app by Fuji Bit Inc..) - Source: https://appshunter.io/ios/app/rojiraku-logic-gate-puzzle/id6826662466 (this page in markdown: same URL + `.md`) - Developer: [Fuji Bit Inc.](https://appshunter.io/developer/1874205957) - Category: Education, Games, Puzzle - Price: Free - Age rating: 4+ - Requires: iOS 17.0 · 11 MB - Languages: American English, Afrikaans, Albanian, Amharic, Arabic, Armenian, Azerbaijani, Basque, Belarusian, Bangla and 62 more - Released: 2026-10-27 - Data updated: 2026-10-27 ## What is ROJIRAKU? ROJIRAKU is a puzzle game for learning how computers work. Connect logic gates with your finger, and step by step you will build all the way up to a working CPU of your own. Phones and AI are, at the very bottom, just switches turning on and off. In ROJIRAKU you don't read about it. You build it with your own hands and see it work. HOW TO PLAY - Read the goal at the top, such as "Light the lamp only when both switches are on" - Place gates and drag from pin to pin to wire them up - Flip the switches: wires that are on fill with glowing red particles, so you see the result instantly - Tap Check to try every combination of switches and clear the stage - There is more than one right answer. Use fewer gates to earn more stars 5 CHAPTERS, 38 STAGES Chapter 1 Gates: NOT, AND, OR, XOR, and building everything from NAND alone Chapter 2 Combinational circuits: binary, half adder, full adder, multiplexer, decoder, 4-bit adder Chapter 3 Memory: latches, flip-flops, counters, registers Chapter 4 The arithmetic unit: two's complement, subtraction, shifts, zero detection, the ALU Chapter 5 The CPU: put a control unit, a program counter, and an accumulator together to finish your CPU WHAT YOU BUILD BECOMES YOUR NEXT TOOL Every circuit you clear becomes a part, and in later stages you can use it as a single box. XOR goes into the half adder, the adder goes into the ALU, and the ALU goes into the CPU. In the final stage, a program runs on the very CPU you built, and the answer to 1 + 2 + 3 + 4 + 5 appears on screen. FEATURES - Touch first, read later. After each stage, a short note explains the circuit and where it is used in real life - Covers logic operations, adders, and CPU basics found in school computer science courses - A calm, textbook-like board: white background, black wires, and just two signal colors, red for on and blue for off - A wire list lets you connect wires without dragging, and the game is playable with VoiceOver - For iPhone and iPad, available in 76 languages PRICING ROJIRAKU is free. There are no in-app purchases or subscriptions, and all 5 chapters are free to play. Each chapter opens when you clear the previous one. To support the app, a banner ad is shown at the bottom of the home screen and the stage list. No ads are shown on the board while you build circuits. You can choose whether to see ads based on your interests (personalized ads) at any time from Ad Settings in Settings. Part of the RAKU series by Fuji Bit Inc. ## Is ROJIRAKU safe? Not enough ratings yet to assess ROJIRAKU. ## Is ROJIRAKU legit? ROJIRAKU: Logic Gate Puzzle appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for ROJIRAKU is 65 out of 100 points across 7 verification signals from App Store and developer data. ## Version history (last 1 release) ### 1.0 — 2026-10-27 No release notes. ## More apps by Fuji Bit Inc. - [RENGOKU: Time Attack Pachinko](https://appshunter.io/ios/app/rengoku-time-attack-pachinko/id6758652751) - [SUUGAKU](https://appshunter.io/ios/app/suugaku/id6759102221) - [BUTURAKU](https://appshunter.io/ios/app/buturaku/id6759213255) - [DENRAKU - Electromagnetism Sim](https://appshunter.io/ios/app/denraku-electromagnetism-sim/id6759393816) - [PAKEDOU](https://appshunter.io/ios/app/pakedou/id6759820254) - [OKURERUNA！](https://appshunter.io/ios/app/okureruna/id6759956971) All apps by Fuji Bit Inc.: https://appshunter.io/developer/1874205957 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-27.*