Kayf vs DLD

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 Fully in English and Arabic with true right-to-left layout. No account, no ads, no data collection. Everything works offline. Kayf is an educational reference. Always follow the manufacturer's manual and a qualified technician for repairs.

DLD is a digital logic design and circuits workbench for your phone. Drop gates onto the bench, wire them together, flip a switch, and watch the signal travel through the circuit in real time. Built for students working through a digital logic design course — and for anyone who wants to see Boolean algebra actually do something. BUILD ANYTHING • 28 components: switches, clocks, Vcc and ground, every standard gate, tri-state buffers, multiplexers, flip-flops, displays and probes • Gates take 2 to 8 inputs — one wide NAND instead of three cascaded ones • Tap a component to reach its settings: input count, clock speed, colour • A work bench far bigger than the screen, with pan, zoom and fit-to-circuit SEE IT WORKING • Current animates along every live wire, so you can follow a signal • LEDs, LED bars, 7-segment and hex displays light up as the circuit runs • A school bell that rings for as long as it has current • Logic probes read out 1 or 0 anywhere you wire one UNDERSTAND IT • Boolean equations written out from whatever you have drawn • A full truth table generated from your circuit, ready to copy out • Conflicting drivers on a net are flagged rather than quietly wrong • A tutorial section covering every gate symbol and its truth table KEEP YOUR WORK • Save and reopen as many circuits as you like • Undo and redo everything • Recolour wires, lamps and blocks however you want to read them COMPONENTS Switch · Clock · Vcc · GND · AND · OR · NOT · NAND · NOR · XOR · XNOR · Buffer · Tri-state buffer · Tri-state NOT · MUX · DEMUX · D flip-flop · T flip-flop · JK flip-flop · Virtual links · LED · LED bar · 7-segment · Hex display · Bell · Probe · Label PRIVATE BY DEFAULT No account. No sign-in. No analytics. No ads. Nothing leaves your device — your circuits are saved on the phone and nowhere else. The app works with no network connection at all.