Most "useful websites" lists are full of tools you've heard of. Another image compressor. Another PDF editor. Another Notion alternative. This is not that list. These three tools came up in different contexts — one from a developer thread, one while trying to solve an annoying cross-device problem, one while scheduling a meeting across four time zones. What they share: they're free online tools, they require no account, and once you find them, you keep going back. PairDrop: Cross-Device File Transfer Without the Headaches The situation: you take a photo on your phone and need it on your laptop in the next 60 seconds. Or you're sitting next to a coworker who needs a file from your Mac, but they're on Windows. Options? Email yourself. Open a cloud storage app. Dig for a USB cable. None of these are good. PairDrop solves this. Open it in a browser on both devices — they need to be on the same network — and the devices appear to each other automatically as floating icons on the screen. Drag a file onto the icon.…