What If vs Kayf

Break the world. Guess what happens. A setup, some drawings, and then it happens. Drop a book and a flat sheet of paper — which lands first? Blow between two hanging apples — do they swing apart, or together? Tap what you think, watch it happen, and then find out why. Every answer is real science, and most of them are things you can go and try at home with a straw, a balloon or a glass of water. YOU ANSWER BY LOOKING Nearly every question is a picture. There is almost nothing to read, so a child who cannot read yet can still play — and the ones who can are not slowed down by paragraphs. NINE WAYS TO PLAY Guess what happens. Set a dial and watch the picture move. Spot the thing that cannot happen. Put three moments in order. Two dials that fight each other. Tap at exactly the right instant. WHAT IS IN IT 326 questions across 6 topics and 82 levels, plus an endless mode that never runs out. NOTHING TO BUY. NO ACCOUNT. ONE VIDEO YOU CHOOSE. Nothing to sign up for. Progress is saved on your device. There is one advert in the game and it is never played at you: run out of coins and you can choose to watch a short video for more. A child who never taps it never sees one, and it is never shown on opening the app, between levels, or while a question is on screen. Leaderboards and achievements are optional — turn them on and your scores go to the platform's own game service; leave them off and the game plays exactly the same. IT WORKS WITHOUT A SIGNAL The questions and the narration are all inside the app, so it plays on a plane, in a car, and anywhere with no connection. From Doodle Theory, the channel that makes 60-second what-if explainers.

Kayf is an illustrated encyclopedia of how things work. Pick any device, from the fan on your desk to the refrigerator, the microwave, your phone, a car engine, a wind turbine or an MRI scanner, and open it up. Every one of the 92 devices is a real 3D model, cut open so you can see inside: turn it in your hands, pull it apart, tap any part to learn what it does, and watch the moving parts run. Glowing streams show where the air, water, refrigerant, fuel or current actually goes. Then follow the animated step-by-step sequence of how the device works, with each part lighting up as it plays its role. Place any device on your desk in AR and walk around it at life size. 92 DEVICES IN 8 CATEGORIES - Home appliances: fan, refrigerator, air conditioner, washing machine, vacuum cleaner, water heater, iron, hair dryer, dishwasher, dryer, sewing machine, dehumidifier - Kitchen: microwave, kettle, blender, toaster, espresso machine, induction cooktop, gas stove, pressure cooker, rice cooker, air fryer, oven - Electronics: LED bulb, loudspeaker, microphone, noise-cancelling headphones, camera, television, remote control, lithium battery, electric motor, transformer, smartwatch - Computing and communication: smartphone, touchscreen, Wi-Fi router, processor, SSD and hard drive, printer, GPS, barcode scanner, fiber optics, Bluetooth - Transport: car engine, electric car, bicycle, jet engine, helicopter, how planes fly, ABS brakes, submarine, drone, elevator, escalator, traffic light - Energy: solar panel, wind turbine, hydroelectric dam, nuclear reactor, generator, power grid, gas power plant, desalination, UPS, geothermal - Everyday mechanisms: lock and key, toilet flush, mechanical watch, zipper, bicycle pump, thermostat, smoke detector, doorbell, digital scale, ballpoint pen, aerosol can, fire extinguisher, faucet, 3D printer, power drill - Medical and science: X-ray, MRI, ultrasound, blood pressure monitor, stethoscope, pulse oximeter, infrared thermometer, microscope, pacemaker, defibrillator, telescope FOR EVERY DEVICE - A full 3D model you can turn, zoom, cut away and take apart - Labelled callouts that name every part on the model - Tap a part to learn its role and material - AR mode: stand the device on a real table and look inside it - Animated how-it-works sequence, step by step - The science: several paragraphs on the physics and the design choices - By the numbers: power, speed, temperature, efficiency, lifespan - Surprising facts, types and variants, safety notes - Related devices and the principles they share THE PHYSICS - 36 principles from electromagnetic induction to Bernoulli, each explained with a formula and everyday examples and linked to every device that uses it - A glossary of more than 110 technical terms in plain words KAYF PRO (one-time purchase) - All 92 devices - Troubleshooting guides: real symptoms, likely causes and what to do - Every quiz: five questions per device, category quizzes and the mixed challenge - Compare two devices side by side Made for iPhone and iPad: on iPad a device's 3D model and its explanation sit side by side, in every orientation. Fully in English and Arabic with true right-to-left layout. No account needed, and all content works offline. The free version shows ads; Kayf Pro removes them. Kayf is an educational reference. Always follow the manufacturer's manual and a qualified technician for repairs.