Kayf: How Things Work

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. See every part, what it is made of and what it does. Then follow the animated step-by-step sequence of how the device actually works, with each part lighting up as it plays its role. 100 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, wireless charger - Computing and communication: smartphone, touchscreen, Wi-Fi router, processor, SSD and hard drive, printer, GPS, barcode scanner, fiber optics, Bluetooth, LiDAR scanner, NFC reader and tag - Transport: car engine, electric car, bicycle, jet engine, helicopter, how planes fly, ABS brakes, submarine, drone, elevator, escalator, traffic light, hydraulic excavator, liquid-fuel rocket engine - Energy: solar panel, wind turbine, hydroelectric dam, nuclear reactor, generator, power grid, gas power plant, desalination, UPS, geothermal, hydrogen fuel cell - 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, industrial robotic arm - Medical and science: X-ray, MRI, ultrasound, blood pressure monitor, stethoscope, pulse oximeter, infrared thermometer, microscope, pacemaker, defibrillator, telescope, CT scanner FOR EVERY DEVICE - Interactive exploded view: tap a part to learn its role and material - 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 ALWAYS-FREE ENGINEERING LAB - What If Lab: make predictions and explore motor, wind and compression models with live graphs - Fault Detective: inspect virtual measurements and identify a fault - Assembly Bench: solve a five-part fan assembly puzzle 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 162 technical terms in plain words KAYF PRO (one-time purchase) - All 100 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 Paid features also offer one-visit trials through optional rewarded ads. A new visit or paid quiz replay requires a new ad. Ads need an internet connection and available inventory. Monthly drops keep their release schedule. Automatic App Store update checks with a manual check in Settings. 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.