Bahushruta
Bahushruta (बहुश्रुत) is Sanskrit for "one who has heard much" — which is how a language is actually learned: by hearing and reading a great deal of it, always just past the edge of what you already know. Not by memorising rules. Not by drilling words you have no context for.
Suka, the parrot of the old Sanskrit story collections, is its emblem: a bird who has heard all the stories. He picks what you read next.
What you actually do here
Every page is one real sentence from a news text in the language, chosen so that all but one or two of its words are already yours. You read it. Any word with a dotted underline is one you have not met — tap it once you know it. That is the whole thing.
Why this is different from a course
There are no lessons and no levels. You are not walked through chapters. The pages are picked against what you know right now, and they follow you: as your known words grow, the texts get harder on their own, and the sentences they come from are the ones you were almost able to read.
And because this works from a root language into its descendants, the vocabulary you learn is not wasted on one language. Sanskrit is the on-ramp to the Indo-Aryan family. Latin to the Romance languages. Middle Chinese to Japanese. Learn the root and the most common words of a family, and the next language in that family is mostly a change of sound, not a fresh start.
The two sets
Your knowledge is held as two things and nothing else: letters you can read (the script) and words you know. That is what the pages are chosen from — no score, no streak, no level.