Schedule Coordinator (schedule.onl.jp)
A web app to coordinate schedules among multiple people. Participants enter their availability for candidate dates using ○/×/△ to find the best time for everyone.
Sales Tax Calculator (saruwakakun.com)
A consumption tax calculator that computes the tax-inclusive price and tax amount from a pre-tax price. Supports the standard 10% rate and the reduced 8% rate for food and periodicals.
Rune Link
A roguelite puzzle game where you place and combine runes on a board to defeat enemy waves. Features class selection, permanent upgrades, and difficulty unlocks. Free to play in the browser.
Ruler (www.piliapp.com)
An online screen ruler tool for measuring distances and sizes on your display. Drag the ruler across your screen to measure elements in pixels, centimeters, or inches.
Rounded Corner Image Generator (web-toolbox.dev)
Free tool for applying rounded corners (border-radius) to images. Adjust the corner radius and download the result as a PNG file.
Roulette (www.piliapp.com)
An online roulette wheel for random selection. Customize items on the wheel, spin it, and get a random result. Useful for decision-making, classroom activities, and games.
Roulette (toolpods.io)
Register items and randomly select one using a spinning roulette wheel. Useful for group assignments and prize draws.
Roll Dice (www.piliapp.com)
An online dice roller for random number generation. Roll one or multiple virtual dice with customizable sides for board games, tabletop RPGs, and classroom activities.
RGBA to RGB Converter (www.oh-benri-tools.com)
An online tool that calculates the final RGB value by combining an RGBA (transparent color) and a background RGB color. Useful for previewing how a transparent color will actually appear.
Reversi (toolpods.io)
Browser-based reversi (Othello). Outflank and flip opponent's pieces to control the board. Includes AI opponent.
Repeat Timer (www.oh-benri-tools.com)
An online timer that automatically restarts when it reaches zero. Ideal for interval training or recurring task breaks, with alarm sound and fullscreen display support.
Relationship Map (atl2.net)
A web tool for creating relationship diagrams. Register people's photos and names to build a visual relationship map. Useful for tracking children's social connections and organizing interpersonal relationships.
