Rainy Day Activity Generator – Online Indoor Fun for Kids
Randomly picks an indoor activity from a curated list sorted by age. No materials, no prep ideas included. Banish boredom.
UD5 Toolkit
Online Cellular Automaton Simulator — Create, explore, and watch life evolve
Preset Patterns — Click to load
A discrete model studied in mathematics and computer science, consisting of a regular grid of cells, each in one of a finite number of states. The grid evolves through time steps according to a set of rules based on neighboring cell states.
Complex patterns and behaviors that arise from simple rules, without any central controller. The Game of Life is a prime example — intricate structures like gliders and logic gates emerge from just four basic rules applied locally.
John von Neumann originally conceived of cellular automata in the 1940s as a theoretical model for self-replicating machines. Conway simplified these ideas dramatically, creating the elegant Game of Life we know today.
Randomly picks an indoor activity from a curated list sorted by age. No materials, no prep ideas included. Banish boredom.
Measure your yard and calculate how many rolls or square feet of artificial grass you need. Includes waste factor for cuts and seams.
Simple grid canvas to sketch your home's layout and mark escape routes and meeting point. Print for practice. Local only.
Enter height and get fall time and impact speed. Simple physics demo. Good for students.
Drag to see how a solar eclipse occurs. Visualize the moon's shadow. Educational and interactive.
Type a word and see which letters can be spelled with atomic symbols (e.g., Co In = CoIn). Fun ciphers.
Find your exact age in years, months, and days. Calculate the time until your next birthday. All date computations are performed locally and accurately.
Enter a first name and guess the approximate age based on historical popularity data. Purely statistical fun.
Enter target RH and room temp to estimate how often to mist or run a humidifier. Quick reference.
Select common materials (wood, plastic, metals) and see density chart. Predict floating. Fun science.
Calculate how many gallons of water to store based on household size and days. Preparedness aid.
Enter number of people and desired duration to estimate the minimum square footage and ventilation CFM for a residential storm shelter.
Enter pond dimensions and filtration type to estimate safe number of adult koi. Prevent overcrowding.
Animated demonstrations of different campfire lay styles (teepee, log cabin, star). Choose the right one for wind and cooking.
Type a list of items to find and generate a printable checklist with checkboxes. Great for parties.
Set watering schedules for multiple plants with visual alerts. Shows which plants need water today based on last watered date. Data stored locally.
Add plants and track when you last watered them. Get a simple visual alert when it's time to water. Local storage.
If device has ambient light sensor, estimate lux level and recommend plant types. Local only.
Plan your time‑lapse by entering desired clip length, fps, and event duration to find the shooting interval and total frames needed. Avoid under‑ or over‑shooting.
Visualize real‑time linear acceleration (excluding gravity). Watch the 3D vector graph move as you shake the device.
Enter a phrase and find all possible anagram combinations (if computationally feasible). Lexicographic fun.
Compute personalized daily water intake based on weight, climate, and exercise intensity. Converts to common cups/ounces. Purely local with no tracking.
Calculate the interest savings and earlier payoff date by switching to bi‑weekly mortgage payments instead of monthly. See the power of an extra annual payment.
View the NASA Astronomy Picture of the Day (APOD) directly in your browser. Read the explanation. No API key needed.
Convert pet age to human years using updated AVMA guidelines (not simple 7:1). Separate calculators for dogs (size-dependent) and cats. Fun & educational.
Fill in feeding, walking, medication details and generate a clear care sheet for your pet sitter. Print or share.
Enter temperature and wind speed (or humidity) to get the 'feels like' temperature. Safety guidelines included.
Enter your weight and activity level to get a recommended daily water intake goal. Reminder to drink up.
Enter appliance usage and see estimated monthly energy consumption. Identify high usage areas.
Go through a room-by-room checklist to identify trip hazards. Print and fix. Prevent accidents.