Spark & Anvil is our sibling project — built by the same people, on the same principles: free forever, no accounts, nothing about you tracked. It's a broad catalogue of playable K-12 learning apps. Below are their science & STEM apps closest to what we do here; the full catalogue lives at sparkanvil.org.
Every link is age-tagged at the source. We only surface tools for ages 9 and up (Fold Commons serves 9–14 and older); each card shows its age band. Links open Spark & Anvil in the same tab.
Selecting a filter updates the list below.
Showing all 60 apps
Spark & Anvil Ages 9–14 Learn how your body moves and stays healthy — name dance positions, locomotor skills, and the Elements of Dance in the Move Lab, build a weekly fitness plan with the FITT formula in the Plan Lab, and…
Spark & Anvil Ages 9–14 Watch a science demonstration that looks impossible, guess how it really works before the reveal, then discover the physics or chemistry behind the wonder. Stage your own science show, and practice…
Spark & Anvil Ages 9–14 The jobs behind the glass, ages 9–14: spend a week backstage at the museum. Free a fossil without cracking it, protect a rare loan, keep the butterflies alive, light a fragile quilt so it lasts, run…
Spark & Anvil Ages 15–18 Design the test, not just take it: spot leakage, find the hard cases, and see how the metric picks the winner. How to trust a number. For teens.
Spark & Anvil Ages 9–14 Explore a cell and a body diagram tap by tap, build an ecosystem food web from producer to decomposer, and practice biology from cells to evolution across 16 kits.
Spark & Anvil Ages 9–14 Build a small living world and keep it in balance. Stock an aquarium or terrarium with producers, consumers, and decomposers in the Biome Builder and watch the balance model react; predict the ripple…
Spark & Anvil Ages 9–14 Run a real chemistry lab in your browser: predict whether a liquid is an acid or a base, then drop the cabbage-juice indicator and watch the color reveal its pH; stack liquids into a density tower to…
Spark & Anvil Ages 9–14 Build circuits on a virtual breadboard, watch the current flow, code a grid robot with blocks, and wire logic gates — the engineering behind every electronic device.
Spark & Anvil Ages 9–14 Slide the CO₂ level and watch a real (simplified) climate model respond — greenhouse forcing, warming, sea level, and sea ice. Predict the warming before the model reveals it, read climate datasets…
Spark & Anvil Ages 9–14 Watch a star live and die in the Stellar Evolution lab, peer inside a black hole and feel gravity stretch time, climb the Cosmic Distance Ladder, and practice astronomy & astrophysics across 16 kits.
Spark & Anvil Ages 9–14 Run an animal hospital — predict the diagnosis, choose the care, watch the animal recover — plus 400 animal-science questions.
Spark & Anvil Ages 9–14 Explore K–8 science by inquiry: 400 questions in sixteen kits, plus predict-then-observe labs — trace the water cycle, build a food web, and wire logic gates.
Spark & Anvil Ages 9–14 Dive the ocean’s zones — predict how pressure, light and temperature change with depth, match deep-sea adaptations, and practice 16 marine-science kits.
Spark & Anvil Ages 9–14 Build a biome diorama for ages 9–14: place the plants and animals so the food web actually holds — a producer to catch the sun, prey for every predator, and everything where it really lives — then…
Spark & Anvil Ages 15–18 Author a planetarium show, ages 15–18: choose a place and a month and the dome stages the real evening sky, then write a five-beat show about the stars, planets, and constellations that are actually…
Spark & Anvil Ages 15–18 Selection has a direction; drift is pure luck — and in a small population, luck wins. DriftForge runs evolution on synthetic beetles: predict an allele’s frequency after a generation of selection…
Spark & Anvil Ages 9–14 Explore Earth as a living web of connected parts. Pull one thread in the Ecosystem Lab — remove the otters, bring back the wolves — and watch the trophic cascade ripple up and down the food chain…
Spark & Anvil Ages 9–14 The Hall of Good Mistakes. Each room holds an idea careful people believed for good reasons. Read why it made sense, then pick the observation that broke it. Two rooms hold right ideas that were…
Spark & Anvil Ages 9–14 Tune the soil, water, and season to find what really limits a harvest, then predict which four-season crop rotation keeps a field healthiest before you plant it. Plus 16 kits of agricultural science…
Spark & Anvil Ages 9–14 The naturalist’s field notebook for ages 9–14: a specimen is in front of you — sort each note into what you OBSERVE (see, count, measure) and what you THINK (a guess about why or what next). It’s the…
Spark & Anvil Ages 15–18 How did a wanting, grabbing primate become a creature that thinks in symbols? Weigh two rival explanations — symbols growing out of shared emotional signals, or a built-in faculty that matures on…
Spark & Anvil Ages 9–14 Fly a wing through a wind tunnel to see lift, drag, and stall for yourself, then predict which paper-plane design flies farthest before you launch it. Plus 16 kits of aerodynamics and flight-physics…
Spark & Anvil Ages 15–18 Predict the physics before it happens — final velocity, momentum, energy, orbits — then a real engine computes it. HS mechanics & more. For teens.
Spark & Anvil Ages 9–14 Run a real fossil dig from excavation to identification, read the age of rock layers, order the eras of deep time, build the tree of life, and practice paleontology across 16 kits.
Spark & Anvil Ages 15–18 Feed a region for thirty seasons. Each season choose the seed, the fertiliser and the water, and a fixed model of rain, prices and soil plays it out. More food, more income, healthier soil, deeper…
Spark & Anvil Ages 9–14 Predict what a plant needs to thrive, then watch the science decide — read a plant’s light, water, soil, warmth, and food and guess which one is holding it back most, before the growth model reveals…
Spark & Anvil Ages 9–14 Run a farm from seed to shelf — predict how a crop will do before you plant it in the Crop-Rotation Lab, trace a loaf of bread back through every pair of hands that grew and carried it in the…
Spark & Anvil Ages 9–14 Predict how heat travels by conduction, convection, or radiation, engineer insulation that wins on R-value, and practice thermodynamics across 16 kits.
Spark & Anvil Ages 15–18 Predict how the alleles will sort, then a real Punnett-square engine computes the cross and proves you right. Genetics, cells, evolution, ecology — for teens.
Spark & Anvil Ages 9–14 Which knot won’t choke down when you pull it? Why does a reef knot fail the moment you join a thin rope to a thick one? And why does a trucker’s hitch let a 20 kg pull cinch a line to 60 kg? A knot…
Spark & Anvil Ages 9–14 The real-sky companion that gets the family OUTSIDE: see tonight’s real Moon phase, pick your part of the world on a map, and learn the naked-eye stars, planets, and asterisms to look for — with five…
Spark & Anvil Ages 9–14 The science of illusions and magic — predict what a classic optical illusion is really doing then reveal the measurement and the reason your brain is fooled, name the scientific principle behind…
Spark & Anvil Ages 15–18 Judge realistic experiments — read a study, predict whether it holds up, then spot the confound or the noise. For teens.
Spark & Anvil Ages 9–14 A hands-on physics lab — predict what happens before the experiment runs: which shot flies farther, which pendulum swings slower, which bulb glows brighter, plus 400 physical-science questions.
Spark & Anvil Ages 9–14 Build with the six simple machines, compute mechanical advantage in the lab, and predict how gear trains trade speed for torque — the engineering behind every lever, pulley and gear.
Spark & Anvil Ages 9–14 Run a friendly clinic: read a patient’s symptoms and vital signs to reason out what’s going on, explore the body system by system, and trace how an outbreak spreads before you choose how to stop it…
Spark & Anvil Ages 9–14 Match antibodies to the microbes they fit, put the immune response in order, and grow a balanced microbiome in the gut, mouth, skin, or soil — plus microbiology, immunity, and microbiome kits. Calm…
Spark & Anvil Ages 9–14 A mineral-identification lab for ages 9–14: an unknown specimen lands on the bench — run the real tests (hardness, streak, luster, heft, magnet, acid, UV, crystal shape) to narrow it down and name…
Spark & Anvil Ages 9–14 Systems thinking — connect ecosystems, cities and economies, then predict how a nudge cascades. Spot reinforcing vs balancing feedback loops and watch stocks fill, drain, and snowball, all…
Spark & Anvil Ages 15–18 Epidemiology you can run, for ages 15–18. Pick a synthetic outbreak, predict what happens, then a deterministic SIR/SEIR model computes it — the curve, R₀, the herd-immunity threshold. Then you…
Spark & Anvil Ages 9–14 Build power plants, balance an electrical grid against real demand, and trace energy through every conversion — the science and engineering behind the power that runs everything.
Spark & Anvil Ages 9–14 Bend, reflect, and split light on a virtual optics bench — set a lens, mirror, or prism and watch a real ray-trace, order the electromagnetic spectrum, and mix colors of light, across 16 optics kits.
Spark & Anvil Ages 15–18 Design under constraints — read a realistic engineering challenge, predict the best trade-off, then check the numbers. For teens.
Spark & Anvil Ages 15–18 A qubit is just two numbers. A gate rotates them. Measurement squares them. That is the whole of quantum — no mysticism, exact arithmetic. Start in |0⟩, apply a gate, and predict the odds: 100%? a…
Spark & Anvil Ages 15–18 Predict what the reaction does — moles, molarity, pH, gas volumes — then a real engine computes it. HS chemistry, no lab coat required. For teens.
Spark & Anvil Ages 9–14 When it rains on a hillside, where does the water actually go? Not wherever it likes — it obeys one rule: roll to the lowest neighbour, over and over, until you reach a low spot and pool. Trace that…
Spark & Anvil Ages 9–14 Discover the science behind cooking — predict what heat does to food, master the food-safety Core Four, and practice kitchen chemistry.
Spark & Anvil Ages 9–14 Design a fair test by choosing what to change and what to measure, run the predict-observe-explain loop, and practice the scientific method across 16 kits.
Spark & Anvil Ages 15–18 Shape follows sequence: predict what a protein segment folds into, what buries in the core, and how one changed letter (sickle-cell) reshapes it. The reasoning behind the AlphaFold era. For teens.
Spark & Anvil Ages 15–18 The science of your sleep, for ages 15–18. Pick a schedule and the two-process model shows your alertness hour by hour — when you’ll be sharp, when you’ll crash — plus your week’s sleep debt. Then…
Spark & Anvil Ages 9–14 Pilot the solar system: tap a planet on the orbit map for real NASA data, take a mission challenge, predict a moon phase before the reveal, and practice astronomy across 16 kits.
Spark & Anvil Ages 9–14 Something enormous has to ride inside a rocket. How would you fold it? Try the accordion, then Miura's fold: pull two corners and the whole sheet opens at once. Predict the packed size, run it, and…
Spark & Anvil Ages 9–14 Explore Earth's engine: tap through the layers from crust to core, name plate boundaries, read a seismograph to locate a quake, predict how a volcano erupts, engineer against hazards, and load a…
Spark & Anvil Ages 9–14 Real citizen science — practise the GLOBE cloud, bird-count and rain-gauge protocols, keep a field log, and read real datasets.
Spark & Anvil Ages 9–14 Wilderness survival — find north by nature, choose the survival priority, build in the right order, and practice 16 outdoor-skills kits.
Spark & Anvil Ages 9–14 Step into the genetics lab: build the complementary DNA strand base by base, transcribe DNA into mRNA and read the codon chart, fill a Punnett square to predict offspring, work backwards from an…
Spark & Anvil Ages 9–14 See sound as a living wave on an oscilloscope, tune a string to its resonant note, and practice acoustics and wave physics across 16 kits — all in your browser, no mic needed.
Spark & Anvil Ages 9–14 Step into the weather lab: read a synoptic panel of pressure, humidity, and fronts to forecast tomorrow, give a percent-chance of rain and see how well-calibrated your confidence is, assemble the…
Spark & Anvil Ages 9–14 Become a Species Detective and identify wildlife from its field marks — group, habitat, diet, when it’s active, size — with no camera needed, build each habitat’s food web and see why energy runs out…
Spark & Anvil Ages 9–14 The phone as a measuring instrument, and every number from the world comes with a wobble. Time a pendulum three times and see the spread: does a heavier weight change the swing? Does a longer string?…
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Fold Commons and Spark & Anvil share a mission — free, open, no-tracking learning tools — and a founder. We surface each other's work so a curious learner can move between structural biology and the wider world of science without an account, a paywall, or a tracker anywhere in sight. We never embed their apps or fetch them while you browse: this page is assembled once at build time from their public apps feed, and every link is age-tagged so nothing unsuitable reaches a younger audience.