🐘

Pink Elephant

A collection of useful micro-apps & utilities

All apps

100 Pirates — Logic puzzles — pirates, prisoners, hats and light bulbs
1v1 — Topview shooting 1v1
2048 — Play 2048 yourself or watch a trained AI agent beat the game
24 — Make 24 using +, −, ×, ÷ and brackets
3D Shooting — 3d Shooting
4D shapes — 4D shapes
A Conflict of Visions — Study companion to Thomas Sowell's book: constrained vs unconstrained visions of human nature
About — Essays and notes — a small, growing library.
Air Conditioner — See-through split air conditioner: refrigerant boils cold inside, gets squeezed hot outside
Air-Operated Ball Valve — See-through solenoid, rack-and-pinion actuator and ball valve, driven by air pressure
Alpenglow — Walk a small cabin and its meadow while the last sun burns on a towering snow mountain above a far lake, with birds and crickets
Analyzer Prep — Process analyzer trainer: pH, gas analyzers, process GC, NIR/Raman, sample systems and validation
Angle on the Bow — Command a WWII submarine: read the periscope, build a firing solution, slip the escorts
APC Prep — Advanced process control trainer: tuning, step tests, MPC, LP optimization and a live loop lab
Apple Catch — Catching apples with your shrinking bucket!
Astro Facts — Explore fascinating astronomical facts and celestial data
Astro Globe — Learn the days and seasons in 3D
Ball — Ball runner
Ball Bearing — 3D deep-groove ball bearing, quarter cut away: balls roll, the cage follows
Battery Circuit — Cutaway AA battery, knife switch and bulb: watch charge flow through the circuit
Battleship Duel — 1v1 naval duel in 3D: guns, torpedoes, islands and straits, one hit sinks
Big Rig — Drive an 18-wheeler: alley docks, tight turns, merges and rail crossings, scored like a CDL exam
Bike Pump — See-through floor pump with pressure colors: when does air enter the tire?
Black hole — A 3D black hole
Blockwright — Sculpt in 3D blocks: fly around, dive inside, repaint thousands of blocks at once; start from a bridge, tank, starship or castle and save your work as a file
Cable Prep — Low-voltage cable sizing, EU and US side by side, with German-English vocabulary
Cactus — Obstacle jump game
Car Due — Oil change, tire pressure and rotation reminders that read your local weather
Cat — Simulated cat
Chance Lab — Chance Lab
Chef — Cooking game
Chicken Bunny — Kids math education
Chinese Food — Discover authentic Chinese cuisine and recipes
City Grand Prix — F1-style street race on a harbour figure-eight, against AI drivers
Coin Count — Flip 8 coins: what is the chance of 4 heads and 4 tails? Kids climb there in 13 small steps
Column Ops — Run a distillation column from the control room: start-up, shutdown, pump trips and interlocks
Concealed Draw — A top-down concealed-carry decision trainer. Realistic timing, realistic consequences
Concentration — Name words that fit the theme.
Connect 4 — Connect 4 game
Coupon Codes — Find coupon codes
Date Counter — Calculate days between any two dates
Day of Year — Find out which day number it is in the year
DC Motor — See-through brushed DC motor: current, magnets and the commutator flip
Death Clock — Life expectancy calculator based on lifestyle
Diary of a CEO — Diary of a CEO
Dig In — Plan, permit, build and stock a backyard fallout bunker, then live in it for 90 days
Distillation Tower — See-through ethanol-water column: vapor climbs tray by tray
Dogfight — 1v1 jet dogfight in 3D: hold the lock, fire one of two missiles
Drift — Endless 3D abstract: four thousand cubes fold through lattices, knots and tunnels
Earth — Spin the Blue Marble and cut it open to the core
Egg vs Hair — A human egg cell beside a human hair, both at true micrometer scale
Eight Ball — Eight-ball pool against the computer on Easy, Medium or Hard, with an aim guide and real fouls
Elevator — See-through traction elevator: brake, motor, counterweight and doors
Escalator — See-through escalator: one drive pulls the steps and the handrail
Ethnic America — Thomas Sowell's Ethnic America, group by group
Eureka! STEM Card Duel — Hearthstone-style card duel with six STEM disciplines; every card carries a real science fact
Exercise — Exercise Tracker
Family Fallout Bunker — See-through minimum family fallout shelter: 7.5 m² under 0.9 m of earth, every bucket on its shelf
Far Fires — Hunter-gatherer life RPG: fair trade and kept promises turn strangers into kin
Faucet — See-through compression faucet: the stem lifts the washer and water flows
Filter Due — Know when to change your HVAC air filter, estimated from your local weather
Fire — Fire Calculator
Fire Mission — 1v1 tank tactics with artillery and fog of war; beat three commanders, then watch a neural net play
Fizz Rocket — Film-canister CO2 rocket in 3D slow motion: pressure, chemistry and the ions behind the pop
Flock Simulation — Flock Simulation
Fluid Simulation — Fluid Simulation
Foucault Pendulum — A 67 m pendulum: pick a latitude and watch the Earth turn under it
Four Cells — Open-card solitaire with four free cells; a solver checks every deal, with undo, hints and auto solve
Four-Stroke Engine — See-through gasoline engine: intake, compression, power, exhaust
Fourier Epicycles — Fourier Epicycles
FPV Factory Run — 3D FPV drone race through an abandoned factory against a ghost drone
Fuel Nozzle — See-through gas pump nozzle: how it shuts itself off when the tank is full
Galaxies — Galaxies crashing simulation
Game Lab — Learn game theory, strategy and more
Garbage Truck — Automated side-loader: the arm grabs the cart, the packer crushes it 4:1
Gem Swap — Endless match-three: swap gems to line up three or more, with new colors as you climb and unlimited hints
Gravity — Gravity and black hole simulation
Gravity flip — Gravity flip game
Great Pyramid — See-through Great Pyramid of Giza: passages, Grand Gallery, King's Chamber
High Bay — Drive a forklift: unload pallets from a trailer and set each load into its rack bay, up to 6 metres high
High Ground — Pick two teams of 1 to 10 bots, drop them on a floating island and watch them fight
Hold Short — Run the tower at a busy two-runway airport: land, line up, take off and cross without an incursion
Hover Duel — 1v1 hovercraft duel on the inside of a closed arena, no gravity
Hull Down — 1v1 tank tactics with fog of war and armor plates; beat three commanders, then watch a neural net play
Hydrogen — Hydrogen electron position
Ice breakers — Ice breakers game
Induction Drop — Drop copper through a coil: eddy currents brake its fall
Inflation — Calculate inflation and purchasing power over time
Influence Lab — Persuasion, used and defused
Intelligence — A Brief History of Intelligence
Investing from Darwin — Study companion to Pulak Prasad's book: avoid big risks, buy quality at a fair price, wait
Jet Engine — See-through turbofan on a test stand: start it up and push the throttle
Lead Time — Work a gunship's sensors: find the convoy among farmers and friends, then lead your shot
Lighter — Cut-away butane lighter: wheel, flint, spark, valve, flame
Line of Fire — 1v1 tank tactics with instant guns and fog of war; beat three commanders, then watch a neural net play
Line Up — Learn the coordinate plane: points, slope, y = mx + b, and where two lines cross
Logic Lab — Think in valid steps and spot fallacies
Loop — Drive around a track
Making Sense — Sam Harris's conversations, one idea at a time
Meadow Farm — Cozy farming: plant nine crops, raise chickens, fish the pond. Nothing can fail
Mechanical Pencil — 3D cutaway mechanical pencil: the clutch feeds 0.5 mm of lead per click
Microphone — Inside — See-through dynamic microphone recording a glockenspiel, slowed 500× to watch sound become voltage
Mind Lab — System 1 and system 2
Minesweeper — Minesweeper with algorithems
Modern House Plan — See-through, fully furnished two-storey modern house to walk through
Molecule Lab — Build real molecules by bonding atoms together
Monster Attack — Monster attack game
Multiplication Mania — Kids multiplication game
Naval — The Almanack of Naval Ravikant
Night Sky — Explore the night sky and constellations
Ninety South — The 1911–12 race to the South Pole: lay depots, survive the night, reach the Pole and walk home
NLTH Dealer — Virtual chip tracker for home games
No Drama Decipline — No drama discipline
Novel Typist 3D — Type classic novels on a 3D mechanical keyboard with finger colors
NVC Lab — Non-violent communication
Offline Book — Offline book
On Tyranny — Twenty Lessons from the Twentieth Century
One Strike — A 1v1 ring-out duel where every hit is lethal, against a neural fighter
Orbit Sweep — Build a space-junk cleaner from today's hardware, launch it and fly it until it dies
Particle simulator — Particle simulator
Past — Past timeline
Pendulum — Pendulum simulation
Pin Tumbler Lock — 3D five-pin lock: insert the key, pins rise to the shear line
Pincer — Six red tanks fight six blue; three blue tanks pass through a turnstile and fight the same battle backward in time
Plaza — Plaza racing game
Power Shots — Jump, flip, and shoot. Crack the treasure chest for new bros and pistols
Präpositionen — German prepositions and word order, as pictures you can click
QR Peek — See the link a QR code hides before you tap it, without the picture ever leaving your browser
Racer — Racing game
Radar Contact — Work approach radar at a busy airport: vector arrivals to the ILS and keep everyone separated
Rain check — Did the Rain water my lawn?
Random Tools — Roll dices, lottery and shuffle groups
Ratchet Wrench — See-through ratchet: flip the lever and the pawl switches direction
Rate My Manager — A world map of bosses, rated 1 to 5 by the people who worked for them. No login, one rating a day
Reality — Loop quantum theory
Recall — Can you remember? Memorize the pattern and recall it perfectly.
Redleg — Command a 155 mm self-propelled howitzer: emplace, lay the gun, adjust fire, then scoot
Redo — Reoccuring todo list
Regatta — 3D sailboat race: steer, trim and fly the spinnaker against AI skippers
ROCE Screen — Return on capital employed for S&P 500 companies over 5, 10, 15+ years, from SEC filings
Rocket Engine — See-through full-flow staged combustion engine, like SpaceX Raptor
Rocky — Rocky from Project Hail Mary
Rolling Coins — How many times a rolling coin spins — the coin rotation paradox
Rubik's Cube — A 3D Rubik's Cube that turns itself through classic algorithms
Sand physical simulation — Sand physical simulation
Scale Navigator — Space scale navigator
Scan — Turn phone photos of documents into clean PDFs, privately
Shanghai Dialect — Learn the Shanghai dialect and phrases
Shape War — Real-time strategy, but only with shapes.
Shatter — Glass-breaking Breakout; hand the paddle to a neural net at any moment, and take it back
Sizing Prep — Control valve, on/off valve and flow meter sizing trainer with interactive labs
Skydive — Skydiving sim: freefall, pull in the yellow zone, land your canopy on target
Skyline Swing — Swing on silk across a city of skyscrapers and race a shadow racer
Snack Attack — Plant healthy food towers to stop the junk food invasion
Snake — Classic snake game
So What — So what
Soap Pump — See-through soap dispenser: piston, stem holes and the ball valve
Solaris — Solar system scale navigator in 3D
Sound Lab — Play a tone, see its wave, stack harmonics into a timbre, and train your ear on intervals
Sous Vide — Sous vide cooking times and temperatures
Space Duel — 1v1 3D space dogfight with lasers, homing rockets and flares against an AI pilot
Space Shooting — Space Shooting
Space Station — See-through 3D International Space Station with every port docked
Sperm to Virus — Zoom from a sperm cell to a poliovirus, all at true scale
Split Bill — Easily split bills among friends
Standoff — A 1v1 tactical shooter against a bot: pick both guns, then win rounds with grenades and smoke
Starship Scale — 124 m Starship at true scale beside a human and a robotaxi
Steam Turbine — See-through six-stage steam turbine driving a generator
Stick Tower — Pull blocks from a wooden tower with real physics, colored by load
Storm Perch — Walk through a glass house hovering above a rainforest in a thunderstorm, with muffled rain, thunder and a piano
Stranded — 2D wilderness survival: signal, find water, shelter and fire, then read your rescue review
Study in Germany — Everyday German for students — real sentences for the Mensa, the checkout, the doctor, the delayed train
Sudoku — Sudoku puzzle game
Superyacht — See-through 90 m superyacht, fully furnished from beach club to helipad
Survival — Live off the land for 100 days in the Canadian boreal forest with only 10 items
Swarm — Top-view shooting game
Sweep Bot — Program a robot vacuum in a Python-like language, watch it clean a dusty home in 3D, speed up time and read the report card
Talk Down — Both pilots are out: a passenger lands the jet, coached by radio through the autopilot and the landing
Tank Duel — 1v1 tank duel in 3D: four battlefields, six weathers, AI opponent
Telescope — Inside — Cut-away telescope for kids: watch light bend through each lens and build Galileo's telescope
Temperature — F/C Temperature converter
Tetris — Classic Tetris game with AI assistance
Text Converter — Text converter
The Far Road — Explorer's journey in the farming age: find a city on an old map and come home alive
The Impossible House — Walk a 3D house that cannot exist: a shed bigger inside, endless stairs, a door with no wall
The Long Wait — 3D fallout shelter survival: keep air and water going, and decide when it is safe to walk out
The Predictive Mind — Study companion to Jakob Hohwy's book: your brain guesses first, then checks; hands-on demos for every chapter
The Psychology of Money — Interactive companion to Morgan Housel's book: all 20 chapters as short reviews you can play with
The Sun — Anatomy of a star, cut open to the fusing core
Thirteens — Pyramid solitaire: pair cards that add to 13; a solver checks every deal, with undo, hints and auto solve
Timezones — Convert times across different timezones
Todo — Simple todo list to manage your tasks
Toilet Flush — 3D cutaway toilet: the siphon empties the bowl, the fill valve refills it
Topview Shooting — Topview Shooting
Tower Defence — Tower Defence
Trade Paint — Stock car racing about contact: draft in a 20-car pack, bump, block and watch the replay of the Big One
TrashBot Park — Program a Raspberry Pi robot in real Python to clean up a 3D park
Trunk Line — A 1v1 mini RTS: shields, pikes, archers and cavalry, stances, fog of war and friendly fire
Trunk Party — Ultimate multiplayer showdown. Fast math, quick reactions, and odd-one-out hunting.
Trunk Tactics — Pick a small party of heroes and outmaneuver enemy waves in turn-based grid battles
Trunk Wars — Push three lanes, topple towers, level your hero, and destroy the enemy citadel
Turkey — The Turkey Who Asks Why
Tusk — An action-RPG rogue-like. Fight, gain powerful abilities, die, and do it all over again.
Two Thousand — 2,000-piece jigsaw of famous paintings with shape, neighbor and color filters plus a magnifier
Typing — Space Typing Game
Virus to Atom — Zoom from a virus to a carbon atom through real molecular structures
Visual Timer — Tap once and a shrinking coloured wedge counts down up to 60 minutes
Water — Water
Werewolf — Werewolf facilitator
White Board — White Board
White House — See-through White House: click any room, from the Oval Office down
Why We Sleep — Why We Sleep
Wingsuit — Wingsuit BASE line: buzz a summit, thread a rock gap, fly under a bridge
Word Counter — Count words and characters in your text with real-time preview
Working Day Counter — Calculate business days between dates
Zero Vis — Land a widebody jet in heavy fog: fly the ILS by hand or switch the autoland on and off at any moment
Zing! History Showdown — Hidden-role card game with 24 figures from history; every card teaches a real quote or date
Zipper — 3D zipper with a see-through slider: how the teeth lock and split
Zodiac Sign — Chinese zodiac sign finder
Zombie Recess — Co-op kids' board game: bonk silly zombies and lock the school gates; seven chapters to unlock

My apps