Here’s a categorized list with direct links:

Writing / Articulation / Flow

WebsiteLinkBest for
Dangerous Writing AppOpenWriting without overthinking; anti-perfectionism. ([squibler.io][1])
750 WordsOpenDaily private journaling habit
OneLook ThesaurusOpenBetter vocabulary and word choice

Cognitive Biases / Rational Thinking

WebsiteLinkBest for
The Decision Lab — BiasesOpenCognitive biases and behavioural science. (The Decision Lab)
Clearer ThinkingOpenFree tools for decision-making, logic, self-awareness. (Clearer Thinking)
LessWrong Rationality A–ZOpenDeep rationality, belief-checking, reasoning errors. (lesswrong.com)
Farnam Street Mental ModelsOpenMental models for better decisions. (Farnam Street)

Philosophy / Ethics / Moral Reasoning

WebsiteLinkBest for
Philosophy ExperimentsOpenMoral dilemmas, logic puzzles, philosophy tests. (Philosophy Experiments)
Moral MachineOpenTrolley-problem style ethical decisions. (Moral Machine)
YourMoralsOpenMoral psychology and values tests. (yourmorals.org)

Logic / Math / Coding Puzzles

WebsiteLinkBest for
BrilliantOpenInteractive math, logic, CS, probability. (brilliant.org)
Project EulerOpenMath + programming puzzles. (projecteuler.net)
Advent of CodeOpenFun programming challenges. (adventofcode.com)
Simon Tatham’s Puzzle CollectionOpenPure logic puzzles. (chiark.greenend.org.uk)

Systems Thinking / Interactive Explorables

WebsiteLinkBest for
Complexity ExplorablesOpenSystems, networks, emergence, simulations. (complexity-explorables.org)
Explorable ExplanationsOpenLearning through interactive simulations. (explorabl.es)
Nicky CaseOpenGame theory, society, trust, anxiety, systems. (ncase.me)

Forecasting / Probabilistic Thinking

WebsiteLinkBest for
Good Judgment OpenOpenPredicting real-world events. ([gjopen.com][16])
MetaculusOpenForecasting, probability, future events. (metaculus.com)

Daily Brain Games / Pattern Recognition

WebsiteLinkBest for
NYT GamesOpenWordle, Connections, Crossword, Spelling Bee. (Google Play)
Lichess PuzzlesOpenChess tactics and calculation. (lichess.org)
Set with FriendsOpenPattern recognition and speed. (setwithfriends.com)
Daily SET PuzzleOpenSolo SET pattern puzzles. (anniehu.com)

My strongest picks for you: Dangerous Writing App, Clearer Thinking, Philosophy Experiments, Brilliant, Project Euler, Complexity Explorables, and Good Judgment Open.

[1]: https://www.squibler.io/dangerous-writing-prompt-app/ "

The Most Dangerous Writing App

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[16]: https://www.gjopen.com/ " Good Judgment® Open

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