Things you can buy

Each one is sold by the marketplace it sits on, which handles the order, the printing and the money.

• Coastline map prints Displate Chart-style coastlines drawn from public-domain survey data, printed on steel.
• Fabric and wallpaper Spoonflower Seamless geometric repeats and clan tartans, printed to order by the yard or the roll.
• Stock artwork Adobe Stock The same geometry as vector and image files, licensed by the download.

Things you can use for nothing

No account, no sign-in, nothing to install.

• Wells wells.romermade.com A daily logic puzzle. Every number is how many steps it is to the nearest well, and nothing needs guessing.
• TideStrip tides.romermade.com High water, low water, sunrise and sunset for any NOAA tide station — as a page, or as one line you can paste into a site.
• Maker Margins makermargins.com Five calculators for handmade sellers: what to charge once fees are taken out, what Etsy really keeps, and whether a craft fair paid for the day.
• Wells Bench bench.romermade.com A deduction benchmark that verifies itself: every instance generated, proved to have one solution, and graded by program.