Crafted for Crisp Retina Displays
Experience clean 2D vector art, lush nature animations, and intuitive tap controls tailored for iPhone, iPad, and Apple Silicon Macs in full landscape orientation.
Stage 1: Wolf, Sheep & Cabbage
Classic 2-shore predator-prey river crossing with boat capacity rules.
Animated Boat Rowing Physics
Wooden oars and water ripples responding to passenger rowing capabilities.
Night Bridge & Torch Riddle
Time & speed optimization under finite lantern oil and fragile bridge limits.
Lotus Pond Animal Swap
Swap frogs and cute animals between lily pads with strict leap rules.
Golden Balance Scale & Ciphers
Ternary balance weighing to isolate the counterfeit disguised wolf.
Decanting Water Jugs
Exact volume measuring using uncalibrated 8L, 5L, and 3L vessels.
Master Brain IQ Certificate
Achieve mathematical minimum trips (S-min) to earn 3-star distinctions.
35 Stages Across 6 Chapters
Comprehensive progression map from classic folklore to grandmaster theory.
Environments Designed for Every Riddle
Each chapter takes place in a distinctly crafted visual realm tailored to its mathematical and narrative logic.
Classic River Shore
Peaceful sunny river banks where farmers, shepherds, wolves, and sheep navigate predator-prey boat crossings.
Midstream Island Haven
Complex 3-shore river networks where travelers use mid-river stepping islands to swap passengers under capacity limits.
Night Lantern Bridge
Moonlit gorge with a fragile wooden suspension bridge. Family members must cross under finite torch oil and varying walking speeds.
Lotus Pond Sanctuary
Serene water garden featuring lotus pads, stepping stones, and delightful hopping frogs and forest creatures.
Golden Balance Vault
An ancient deduction hall housing ornate brass balance scales to isolate counterfeit coins and uncover disguised wolves.
Decanting Workshop
A precision measuring laboratory with liquid carafes, where players measure exact volumes using uncalibrated 8L, 5L, and 3L jugs.
Characters, Creatures & Constraints
Every passenger in River IQ has distinctive boarding rules, rowing abilities, or predator-prey dynamics.
Controls the wooden boat, rows across the river, and keeps the wolf safely separated from the sheep.
Will happily eat the crisp cabbage if left alone without the Farmer's watchful supervision.
Must never be left alone on either riverbank with the defenseless sheep when the boat departs.
Harmless on its own, but irresistible to the hungry sheep if left unattended on shore.
Can row the boat. Monks must never be outnumbered by demons on either shore at any time.
Also skilled at rowing. Will overpower the monks if their numbers exceed monks on the same bank.
The only authority qualified to transport the thief and keep other passengers safe from mischief.
Will harm family members if left on a riverbank without the supervising Police Officer.
Hops one stone forward into an empty pad, or leaps over one adjacent companion into an empty space.
5 Specialized Puzzle Engines
Unlike generic puzzle apps, River IQ is powered by 5 purpose-built sub-engines modeling distinct mathematical and computer science state machines.
River Crossing
2-shore & 3-shore island ferry mechanics with pilot qualifications, boat capacity, and mutual predator-prey rules.
Decanting Jugs
Exact volume measuring with liquid jugs (8-5-3L & 16-11-6L) with pour, fill, and empty state trees.
Night Bridge
Dark bridge crossings with speed-differing family members and finite lantern/hourglass fuel constraints.
Scale & Cipher
Ternary balance weighing to isolate counterfeit coins plus multi-dial digital cipher locks.
Board Grid
Frog swap leaps, Tower of Hanoi discs, Knight's Tour, Peg Solitaire, and Klotski sliding blocks.
Everything You Need to Master the Waters
Discover the features that make River IQ an indispensable mental exercise for puzzle aficionados, students, and educators.
6 Master Chapters
Journey from Chapter 1 (Classic Foundations) through Chapter 2 (Tribal & Island Ferries), Chapter 3 (Night Bridges & Jugs), Chapter 4 (Ciphers & Combinatorics), Chapter 5 (Chess & Grid Relocations), up to Chapter 6 (Grandmaster Algorithmic Challenges).
Real-Time BFS Hint Solver
Need guidance? The built-in Breadth-First Search (BFS) graph explorer runs locally on your device CPU, traversing state space to pinpoint the mathematically exact next move without giving away the full solution all at once.
Instant Undo & Restart
Puzzles are about exploration, not punishment. Rewind your trips step-by-step with zero penalty, explore counter-intuitive paths, and reset board states instantly whenever fresh inspiration strikes.
10 Localized Languages
Fully translated into English, Vietnamese (Tiếng Việt), Spanish (Castilian & Latin American), French, German, Danish, Korean, Japanese, and Turkish. Switch seamlessly with a single tap in the in-game modal.
Universal Landscape Adaptation
Designed from the ground up for landscape orientation (1280x720 base viewport). Enjoy ample breathing room on iPad Pro, seamless touch controls on iPhone, and native keyboard/mouse support on Apple Silicon Macs.
100% Private & Kid-Safe
No analytics SDKs, no behavioral trackers, and no mandatory online accounts. All progress is saved strictly locally to your device. Perfect for children, schools, flights, commutes, and quiet offline sessions.
🛡️ App Store Review Guidelines & Privacy Compliance
River IQ is engineered to exceed the highest quality and safety standards mandated by Apple's App Review Guidelines:
🎨 Guideline 2.3.14 (Creative Assets)
All screenshots, posters, and icon assets depict authentic native in-game gameplay rendered directly by the Godot engine. No deceptive 3D trailers or false features.
⚙️ Guideline 2.5.19 (No Hidden Code)
100% self-contained binary. Contains zero hidden backdoors, zero remote code execution, and zero dormant server-toggled features.
👨👩👧👦 Guideline 1.2 & 5 (Family & Child Safe)
Zero user-generated content (No UGC), zero messaging or chat, and zero objectionable themes. Rated 4+ for children and family education.
💎 Guideline 3.1.1(a) (100% Free / No IAP)
Completely free to play with zero In-App Purchases, zero paywalls, zero subscriptions, and zero external payment links.
🔒 Privacy Manifest (Zero Data)
Includes certified PrivacyInfo.xcprivacy with NSPrivacyTracking = false. Absolutely no personal or diagnostic data is harvested.
About Developer NGOC THANG TRUONG
Independent software & game developer crafting high-fidelity simulation sports, mathematical logic puzzles, and privacy-first utilities for Apple platforms.
NGOC THANG TRUONG
Creator of original digital titles across iOS, iPadOS, and macOS. Portfolio highlights include Carom GO (realistic 3D carom billiards simulation), River IQ (classical algorithmic river crossing puzzles), and MiniStats (native Apple Silicon system monitor). Designed with an uncompromising commitment to 100% ad-free gameplay, local data privacy, and clean offline performance.
App Store Technical Specifications
Common Questions
Everything you need to know about gameplay mechanics, hints, and device support.
🚣 How do the river crossing rules work?
Each riddle features specific constraints: a maximum boat capacity, designated pilots, and forbidden combinations (e.g., leaving the Wolf alone with the Sheep, or Demons outnumbering Monks). Tap entities on the shore to board, then tap the destination shore to row across.
💡 What does the Hint button do?
The Hint button activates our on-device Breadth-First Search (BFS) graph solver. It analyzes your current state and provides the single next optimal move to navigate out of dead ends without giving away the full solution all at once.
🧠 How is the Brain IQ Certificate calculated?
Each puzzle has an optimal number of trips (S-min). Solving in the minimum moves awards an official 3-star Master Brain rating and IQ Certificate. You can replay any stage at any time to optimize your move efficiency.
📱 Can I play on iPad and Mac?
Yes! River IQ is a Universal iOS application compiled with arm64 native support for iPhone, iPad, and Apple Silicon Macs (M1/M2/M3/M4) with a responsive UI that scales crisply to any aspect ratio.
🌐 How do I switch languages?
Tap the Globe icon (🌐) on the Main Menu or in the in-game header. River IQ supports 10 languages: English, Vietnamese, Spanish (Castilian & Mexico), French, German, Danish, Korean, Japanese, and Turkish. All translations switch instantly without restarting.
📶 Does River IQ require an active internet connection?
No. River IQ is 100% self-contained and completely playable offline — ideal for flights, commutes, family road trips, and off-grid relaxation.