Computer Science
44 apps to play — grouped by age.
🎈 Ages 6–8 · Grades 1–3
PathPals
Ages 5–8 · Gr K–3 Level 1
Choose the moves that guide a friend along the path to the goal — early sequencing, directions, loops, and debugging (pre-reader computational thinking) with Roami and friends, made for the youngest learners.
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MotionPals
Age 6 · Gr 1 Level 1
A ScratchJr-style block-animation studio for ages 6–8: snap Move, Look, Say and Repeat blocks onto Zip the robot to make it walk, spin, grow and speak — then press Run and watch your program go. Copy your dance as a little cartridge code to share with a friend, or paste theirs to remix it. No accounts, no server, nothing to buy; everything stays on your device.
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QwertyPals
Ages 6–8 · Gr 1–3 Level 1
Learn to touch-type the friendly way — QwertyPals starts you on the home row, where 8 little house-characters live on 8 keys (one per finger). Get every letter right first, then a little faster. No ads, no account, no AI — just you and the keyboard, right here in the browser.
Play QwertyPals →
RobotPals
Ages 6–8 · Gr 1–3 Level 1
You are the Coder: give the Robot steps — Forward, turn Left, turn Right — then press Run and watch it walk the grid to the flag. RobotPals teaches the first idea of coding — an exact list of steps, run in order — with big buttons, sounds, and no way to lose (a bump just says "fix your steps and try again"). Play it with a friend: one codes, one is the Robot. On-device, no account. Ages 6–8.
Play RobotPals →
🎒 Ages 9–14 · Grades 4–8
AIForge
Ages 9–13 · Gr 4–8 Level 2
Learn how AI really works — and how to be a smart digital citizen. Train a classifier by labelling examples and watch it discover a rule (then see the rule and WHY it decided), catch bias in a skewed dataset and fix it, and spot deepfakes and misinformation — plus 16 kits on AI, machine learning, ethics, privacy, and fairness. Everything runs on-device: no accounts, no data collection, no real AI calls.
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RoboForge
Ages 11–13 · Gr 6–8 Level 3
Program a robot with drag-in code blocks — move, turn, loops, and sensors — and watch it run a grid to the goal; program a factory sorter with if/else rules; and practice robotics across 16 kits. On-device, no accounts.
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NeuralQuest
Ages 10–13 · Gr 5–8 Level 4
Learn how AI really works by building it — no coding. Label your own examples and watch a classifier discover a rule (then see the rule and WHY it decides), predict what a recommender serves you next and uncover filter bubbles, popularity bias, and feedback loops, and practice AI & machine-learning literacy across 16 kits on ML, neural networks, ethics, and computer vision. Everything runs on-device: no accounts, no data collection, no real AI calls.
Play NeuralQuest →
TraceForge
Ages 10–13 · Gr 5–8 Level 2
Read a short program, predict what it prints, then step through the real trace — line by line, watching each variable change — to see exactly how code runs in your head. A read-before-run coding lab. Ages 9–14.
Play TraceForge →
CommandForge
Ages 9–13 · Gr 4–8 Level 2
Type plain commands — set, move, repeat, define — to build a block world, and a real interpreter runs them on your device. A friendly text-command language between drag-blocks and code. Ages 9–14.
Play CommandForge →
BugTales
Ages 10–13 · Gr 5–8 Level 3
Every character has one recurring bug. Read the program they submitted, mark the line that is wrong, then reveal the fix and write the bug report — the real debugging loop. A read-to-debug coding lab. Ages 9–14.
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SyntaxForge
Ages 9–13 · Gr 4–8 Level 2
Build a short program to hit a goal — taking the training wheels off one at a time: tap whole-token tiles into the blanks, then type with a palette, then write it all yourself. The engine runs what you built and tells you exactly where the syntax went wrong. A make-it-print coding lab. Ages 9–14.
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GateForge
Ages 10–13 · Gr 5–8 Level 3
Wire logic gates — AND, OR, NOT, XOR, NAND — into a real circuit, flip the switches to watch it light up, and climb the gate→adder→selector ladder step by step toward a CPU. A hands-on digital-logic lab. Ages 9–14.
Play GateForge →
ScriptQuest
Ages 10–13 · Gr 5–8 Level 3
Read a tiny program, guess what it will do, then run it and watch the hero walk. When it breaks, Semi the ant asks a question and you pick the fix. A one-tap Blocks↔Text switch shows the same script both ways — the bridge from block coding to real text code. Deterministic and on-device; nothing leaves your device.
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EventForge
Ages 9–13 · Gr 4–8 Level 2
When this happens, do that. An app doesn’t run top-to-bottom — it sits and reacts: a tap, a shake, a clap, a timer ticking on its own. Read the handlers and the event timeline, predict the output log (which lines print, in what order), then watch it run. Event-driven thinking — the shape of every real app. A read-the-events lab. Ages 9–14.
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DoodleForge
Ages 9–13 · Gr 4–8 Level 2
Draw it with a loop. A pen goes forward, turns, and repeats — and out comes a square, a star, a spiral, a flower. Read the little program (a for-loop, a turn, a growing length), predict the picture it draws, then watch the pen make it. The Logo turtle, re-imagined as a read-before-you-run puzzle — the clearest way to SEE what a loop does. A draw-with-code lab. Ages 9–14.
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RailForge
Ages 9–13 · Gr 4–8 Level 2
Drive the cart to the ore — and prove it can be done. Read a little program (move, turn, “keep going while you can”), predict the route the cart takes across the track, then watch it drive. Walls block, the edge stops you, and a built-in solver guarantees every puzzle really is solvable and tells you the shortest program. Read-before-you-run navigation — the loops-and-logic of getting somewhere. A drive-the-code lab. Ages 9–14.
Play RailForge →
TinkerForge
Ages 9–13 · Gr 4–8 Level 3
Change one line, predict the diff. Read a little program that stamps shapes — a row of circles, a growing trail, a grid, some rain — and see what it draws. Then one line changes (a count, a shape, a coordinate, an operator, an if’s threshold): predict the new picture before you run it. Real tinkering is a small change, a careful guess, a look — not button-mashing. A read-before-you-run lab. Ages 9–14.
Play TinkerForge →
ScreenForge
Ages 9–13 · Gr 4–8 Level 3
Design the app before you code it. Read a little screen’s code (a Text, a Toggle, an if, a Button), see the screen it makes, then TAP a control and predict the new screen. A screen is just the view re-reading its state — and a tap is an action that changes that state. Add, set, toggle; an if shows a line only when its test is true. A design-and-see lab. Ages 9–14.
Play ScreenForge →
SortTales
Ages 9–13 · Gr 4–8 Level 3
Five ways to sort a list — and a surprise: the FASTEST one depends on the list. Meet Bubble, Insertion, Selection, Quick and Merge, then predict how many comparisons each makes and watch the bars race. You will feel "Big-O" for yourself — why the simple sorter wins on an almost-tidy list, and why the clever one wins when the list is a mess. Real, tiny, deterministic sorters run right in your browser. Ages 9–14.
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TokenTales
Ages 9–13 · Gr 4–8 Level 3
Ever wonder how AI "writes"? Train a tiny model on a nursery rhyme, then predict what it will say next — and discover the secret: a language model just counts which word tends to follow which, then guesses the most common one. TokenTales builds a real (tiny) next-word model right in your browser — no chatbot, no internet, nothing leaves your device — so you can see exactly how the trick works, and even watch the model write. Ages 9–14.
Play TokenTales →
PairForge
Ages 10–13 · Gr 5–8 Level 3
Read code with a partner. One of you is the Navigator (you read the program and predict what it prints); the other is the Driver (you check it — agree, or read it differently, then talk it over). Two sets of eyes catch the misread one set misses. Reveal the real trace, keep a pair streak, swap roles. Ages 9–14, two players on one screen.
Play PairForge →
PingForge
Ages 9–13 · Gr 4–8 Level 3
The internet isn’t a cloud — it’s real machines with real addresses, and your data hops between them one router at a time. Type a name and DNS finds the number; send a packet and watch it hop across routers on a TTL budget; hit a cache, a handshake, a firewall. Predict each step, then trace the whole route yourself. All exact, all on your device. Ages 9–14.
Play PingForge →
🎓 Ages 15–18 · Grades 9–12
BehaviorForge
Ages 15–18 · Gr 9–12 Level 4
Watch BFS, Dijkstra and A* search the same grid: all three find an optimal path, but a good heuristic makes A* explore far fewer cells. Classical game AI — how an NPC finds its way. Ages 15–18.
Play BehaviorForge →
ReviewForge
Ages 15–18 · Gr 9–12 Level 4
You don’t write the code — you review it. A deterministic assistant, "Auto", submits a function against a spec; your job is to pick the test that catches its bug, find the faulty line, request changes, and confirm the fix. The reviewer’s skill for the agent era — and the assistant never hands you the answer. A code-review lab. Ages 15–18.
Play ReviewForge →
VoxelEngine
Ages 15–18 · Gr 9–12 Level 5
See how a voxel world is really built: dial the fBm octaves and watch procedural terrain gain coastlines and ridges, then see how run-length encoding stores it. Engine-level systems CS. Ages 15–18.
Play VoxelEngine →
LibraryForge
Ages 15–18 · Gr 9–12 Level 4
Read other people’s code. A small helper arrives from an open-source package — read its doc-comment and its code, predict what it prints, then answer the question an assistant never will: what breaks if one line changes? The skill for the age of a thousand dependencies. A code-reading lab. Ages 15–18.
Play LibraryForge →
PackForge
Ages 15–18 · Gr 9–12 Level 4
Mods are data. Fix a broken content pack — bad rarities, impossible stack sizes, clashing ids — until it fits the schema and passes its tests. The discipline behind data-driven modding. Ages 15–18.
Play PackForge →
SpecForge
Ages 15–18 · Gr 9–12 Level 4
Direct an AI agent — the skill for the agent era. You write the brief; a deterministic on-device agent does the work and shows its whole trace. But agents make confident mistakes: a fabricated citation, a wrong unit, an off-brief detour, a leaked detail. Your job is to catch them and fix the BRIEF (not the output), and re-run until it runs clean. Specification, verification, accountability. Ages 15–18, on-device, no cloud calls.
Play SpecForge →
StudioDojo
Ages 15–18 · Gr 9–12 Level 5
A game-design studio for ages 15–18: take an idea from a one-line pitch to a shipped design — scope, build, playtest with a printed rubric on real people, revise, ship. Your coach only asks; the design is yours. Ship a design code you keep plus a real Roblox Studio (Luau) starter. On-device; nothing uploads.
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ChallengeForge
Ages 15–18 · Gr 9–12 Level 5
Judge the three-minute app. A student-showcase entry lands on your desk with a rubric — read what it actually is, decide if it clears the bar (and if not, which pillar it breaks), then reveal the verdict and the fix. The skill a maker needs to ship: reading your own work the way a judge will. A rubric-judgment lab. Ages 15–18.
Play ChallengeForge →
ShipForge
Ages 15–18 · Gr 9–12 Level 5
The paperwork of shipping an app. An entry lands on your desk with a store rule — will it upload, pass review, earn the rating it claims? Read the submission, predict the verdict, then reveal the fix. The half of making a maker never sees until the store rejects it. A submission-review lab. Ages 15–18.
Play ShipForge →
FlowDojo
Ages 15–18 · Gr 9–12 Level 3
Design a routine: pick a "when," add the steps, reorder them, and read it back as a clear sequence — the if-this-then-that idea. No score, no streak. On-device; nothing leaves your device.
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LocaleForge
Ages 15–18 · Gr 9–12 Level 4
Make your app speak every language. A person reads “phở” as three letters — but the software sees three letters, five bytes, and (decomposed) more code points than that. Read a word, a label, a sorted list; predict what the software counts, picks, or orders; then check it against the real Unicode and Intl engines. Software internationalization — where “how long is this word?” has more than one true answer. A read-the-strings lab. Ages 15–18. Vietnamese first.
Play LocaleForge →
KindForge
Ages 15–18 · Gr 9–12 Level 4
Let the compiler catch it. Read a program and predict what the compiler will say — will it compile, or does a type error stop it? If it compiles, what does it print? If it doesn’t, fix it — without changing what it was meant to do. Swift’s types catch a whole class of bugs before the code ever runs. A will-it-compile reading lab across engine-verified programs. A teaching subset of the Swift language. Ages 15–18.
Play KindForge →
FilterForge
Ages 15–18 · Gr 9–12 Level 5
Design a chat-safety filter and measure it honestly (ages 15–18): on a fully synthetic message set, set the risk threshold and rules that flag grooming, off-platform lures, and age-band mismatch — then face the two error costs on a real confusion matrix. A false alarm silences a child talking to a cousin; a miss lets the lure through. There is no perfect line. Deterministic; on-device; nothing leaves your device.
Play FilterForge →
StateForge
Ages 15–18 · Gr 9–12 Level 5
The screen is a function of state. Read a typed struct state + a declarative view and reason about it: what screen does it show? Tap a control — what shows now? And when a stored value goes stale after an event, redesign it — derive, don’t store. The declarative-UI thinking behind every modern app. A state-reasoning lab across engine-verified puzzles. A teaching subset of the Swift language. Ages 15–18.
Play StateForge →
SyncForge
Ages 15–18 · Gr 9–12 Level 5
How does a shared world stay shared (ages 15–18)? Set the tick rate, latency, and whether you use interpolation or rollback, then predict what two players see across 200 ms of lag before the engine runs both screens side by side. See why cheaters exist, why the server must be the authority, and try the unfixable exercise: keep a world consistent with no server. Deterministic; on-device; nothing leaves your device.
Play SyncForge →
AccessDojo
Ages 15–18 · Gr 9–12 Level 5
A blind user opens your app. What does the screen reader say? AccessDojo hands you real screens as code — an icon button with no label, text too faint to read, headings that skip a level — and you predict the audit, then fix it until the problem count hits zero. Run a real accessibility auditor on your device: VoiceOver order, contrast, labels, structure. Ages 15–18.
Play AccessDojo →
QueryForge
Ages 15–18 · Gr 9–12 Level 2
Read a SQL query, predict the exact result set — which rows, in which order — then run it to check. QueryForge shows you a table and a query, and asks you to think through WHERE, ORDER BY, DISTINCT and LIMIT before you press run (the habit that catches a bug before it ships). Every wrong choice is a real misreading the engine actually produces, so you learn where queries trip you. No timer, no score to chase; on-device, no account. Ages 15–18.
Play QueryForge →
RaceForge
Ages 15–18 · Gr 9–12 Level 3
Two tasks. One shared counter. What could go wrong? Predict the smallest value a data race can produce, watch the exact interleaving that loses an update, then wrap it in an actor and see the race vanish. RaceForge enumerates every possible interleaving on your device — no guessing, no magic — so you can feel exactly what Swift 6 is protecting you from when it checks concurrency at compile time. Ages 15–18.
Play RaceForge →
CodeForge
Ages 15–18 · Gr 9–12 Level 5
Read real code, predict what it prints, then run it — a live interpreter proves you right. Loops, functions, lists, debugging. For teens.
Play CodeForge →
GenForge
Ages 15–18 · Gr 9–12 Level 5
Predict what the generative rule will draw, then a real seeded engine runs the code and proves you right. Creative coding — pattern, randomness, color, shape & sound — for teens.
Play GenForge →
ModelQuest
Ages 15–18 · Gr 9–12 Level 5
Judge an AI fairly — compute what a model really does, then weigh the value trade-offs of deploying it. For teens.
Play ModelQuest →
VaultForge
Ages 15–18 · Gr 9–12 Level 5
Crack real codes — read a scrambled message, predict what it says, then break it. Caesar, Vigenère, frequency analysis. For teens.
Play VaultForge →