Tilia turns the books you already want to read into your personal vocabulary builder.

Upload any book (EPUB, PDF, or TXT) or pick one from the built-in catalog of free books. Tilia scans every word, compares it against your vocabulary level, and surfaces only the words you don't know — as flashcards, quizzes, and instant in-context definitions. No canned word lists. No textbook sentences. Just the vocabulary of the books you love, at exactly your level.

HOW IT WORKS
1. Take a short vocabulary test — Tilia estimates how many words you
know (most people are surprised).
2. Add a book: upload your own or choose a classic from the catalog.
3. Read. Words above your level become flashcards automatically, each with the sentence where you first met it. In reader, long-press any word to define and save it.
4. Review with spaced repetition. Cards are scheduled with proven
algorithms, so words come back right before you'd forget them.

READ WITH FRIENDS
Start a co-read and invite friends — even if they don't have the app yet.
Share highlights, reply and react right on the page, and keep each other going
to the last chapter.

WHY READERS PICK TILIA
• Personalized: auto flashcards and quizzes only show words YOU don't know
• Real context: every word is learned in the sentence you found it in
• Smart dictionary: understands inflections — tap "swung" and learn "swing"
• Adaptive assessment that pinpoints your vocabulary size, not a guess
• Read, highlight, and discuss books with friends or alone
• Daily goals and optional reminders to keep your reading habit alive

FREE TO START
Read two books free, one co-read, forever. Go Pro for an unlimited library and unlimited co-reads.

Whether you're an English learner pushing toward fluency, a student prepping
for the SAT or GRE, or a lifelong reader tired of skipping words you don't know — Tilia meets you at your level and grows with you.