Knife Sharpening Angle Trainer – Hold Your Pocket Stone Correctly
Use your phone's gyroscope to practice holding a knife at exactly 20° on a flat stone. Build muscle memory for field sharpening.
UD5 Toolkit
Use your phone's gyroscope to practice holding a knife at exactly 20° on a flat stone. Build muscle memory for field sharpening.
Drag and drop randomly positioned numbers into ascending order as quickly as possible. Compete against your own best time with increasing set sizes.
Listen to a list of spoken random words and type them back in order. Tests and trains your auditory echoic memory with adjustable list length.
A sequence of colors flashes briefly; repeat it correctly. Levels increase in length to progressively challenge your short‑term memory.
Watch a sequence of lights flash on a grid and repeat it back. Similar to the classic Simon game, but with configurable grid size and speed.
A random letter appears; you must select the correct semaphore position from 4 choices. Scouts & maritime.
Randomly prompts you to press a Windows keyboard shortcut (e.g., Win+E). Learn to be a power user.
Practice carrom shots on a virtual board. Visualize rebounds and plan your strike on the physical board.
Paste text and set display speed for Rapid Serial Visual Presentation. Train your reading speed.
Select a tool (VS Code, Figma, etc.) and get random shortcut prompts. Press the keys to practice.
Practice mental arithmetic with customizable operators and digit count. Timed rounds, score tracking. Works offline. Improve your brain speed.
Classic memory card game with emoji or color themes. Select grid size and try to find all pairs in minimum moves. Brain training fun.
Simulate memory page reference strings with FIFO, LRU, and Optimal algorithms. See page fault count. OS concept demo.
See how WeakMap and WeakSet work. Add objects as keys and watch references. Understand memory‑efficient collections.
Random letters appear; you must type the correct code word quickly. Beat your high score. Learn the NATO alphabet.
Flashcards for learning Braille. See the dot pattern and type the letter. Track your speed and accuracy. Accessibility education.
Classic flip‑to‑match pairs game. Choose grid size and card theme. Tracks moves and time. All local.
Display used/total/limit JS heap size using performance.memory. Take snapshots and see growth. Simple memory leak detection.
Choose tabular‑nums, diagonal‑fractions, ordinal and see the effect on a numeric list. Elegant data presentation.
Solve random arithmetic problems under a time limit. Track your score and improve mental calculation. No data collected.
Generate a small logic puzzle grid (like Einstein’s riddle) with clues. Solve in browser or print. Local generation.
Convert any integer up to 3999 into its Roman numeral representation and vice versa. Quick and accurate. Local.
See how many tabs you have open and estimate memory usage based on navigator object. Fun productivity check.
Watch and repeat the growing sequence of colored buttons. How long is your memory? Classic electronic game replica.
Practice sending Morse code using a virtual straight key. Visual feedback and audio tone. Learn timing and proper fist.
A random note appears on the grand staff; click the correct piano key. Improve sheet music reading. Multiple clefs.
A random note name appears; click the correct position on the bass fretboard. Beat your time and accuracy.
See a random letter/number and tap the Morse sequence. Instant feedback. Practice the full international Morse alphabet.
Watch a color sequence and click the same pattern. Gets longer each round. Test and improve your working memory. All local.
Repeat the growing color sequence. How far can you go? Classic memory game with sound and animations.