Inoh Docs
Inoh is a vocabulary app for the articulate. You keep decks of word cards, and Inoh schedules them so a word comes back just before you would have forgotten it.
Open app.inoh.app and Inoh walks you through it: pick five words, and they land in a deck. No account is needed to look around, and you are asked to sign in at the point where something has to be saved.
Beyond searching the dictionary, you can paste an article and Inoh pulls the words worth learning out of it, or browse a public dictionary like The Silicon Valley Dictionary. You can also add words by talking to an AI assistant, which is what Connect an AI covers.