Comparison

Machine Elements 3D vs Kayf

Price, ratings, monetisation and update history for both apps, side by side โ€” with what reviewers say about each.

Head to head
About

Machine Elements 3D

Features
Read full description

Machine Elements turns mechanical engineering into a visual, hands-on learning experience. Follow a structured path from forces, materials, and tolerances to shafts, bearings, joints, power transmissions, gear systems, and gearboxes. Each lesson combines concise engineering explanations with purpose-built diagrams, motion, and quick checks. Open interactive 3D assemblies to rotate and zoom mechanisms, select individual parts, hide components, and inspect how real assemblies are built. Explore bearings from the inside, compare gear arrangements, and see how shafts, couplings, belt drives, chain drives, manual transmissions, automatic transmissions, and CVTs transfer motion and load. Features: โ€ข Guided learning path with visible lesson progress โ€ข Detailed lessons from fundamentals to advanced mechanisms โ€ข Animated engineering diagrams โ€ข Interactive 3D models with rotation, zoom, selection, and exploded views โ€ข Focused quizzes with explanations โ€ข English, Russian, Spanish, and Greek interface languages Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Kayf

Features
Read full description

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.

Screenshots

Machine Elements 3D2 screens
Kayf4 screens

Verdict

The call

The clearest difference is in-app purchases: Machine Elements 3D at none against Kayf's 1. Machine Elements 3D also leads on update cadence (every 2 days vs every 5 days). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Kayf sells 1 one-off in-app purchase. Machine Elements 3D asks for nothing beyond the download.

UpkeepUpdate frequency

Machine Elements 3D ships an update every 2 days, Kayf every 5 days. The most recent releases landed on September 21, 2026 and October 9, 2026 respectively.

Scorecard2 real differences ยท 4 level
Machine Elements 3D versus Kayf: the parameters behind the verdict, then further details
ParameterMachine Elements 3DKayf
PriceFreeFree
Update frequencyEvery 2 days โ€” betterEvery 5 days
AdsNoNo
In-app purchasesNo โ€” betterYes
DevicesiPhone, iPad โ€” betteriPhone
Requires iOS18.518.0 โ€” better
Further details โ€” not scored
Size53 MB18 MB
Age rating4+4+
DeveloperAlexander KutsybalaTariq Al-aqrabawi

In-app purchases

None

Machine Elements 3D

No in-app purchases

1 purchases

Kayf

One-time1
  • Kayf Pro$4.99

Questions

Is Machine Elements 3D free?
Machine Elements 3D is free to download, with no in-app purchases.
Is Kayf free?
Kayf is free to download, with in-app purchases available.
Do Machine Elements 3D or Kayf have ads?
Neither Machine Elements 3D nor Kayf shows ads.
Which is updated more often, Machine Elements 3D or Kayf?
Machine Elements 3D ships an update every 2 days, and Kayf every 5 days. Most recently, Machine Elements 3D was updated on September 21, 2026 and Kayf on October 9, 2026.

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