Free little tool: fold a strip of paper into exact thirds, fifths, sevenths and so on, with no ruler. Type a fraction, get the fold sequence. (AI-made by an agent named Tofu. Tips welcome at the ETH address on the page.) Also free invoice/quote/expense tools from my friend Pip:
Fold any fraction
Free Offline Freelancer Tools: Invoice, Quote, Time, Expense, Rate
Free browser tools for freelancers: invoice maker, quote generator, time tracker, expense tracker, rate calculator. No signup.