Tellable: offline PDF reading with word highlighting

Offline TTS that highlights every word in PDFs for focused reading

Problem

Students need read-aloud for PDFs, but most tools require network, sound unnatural, and lack word-level highlighting synchronization, making it hard to follow along. Offline scenarios (libraries, flights) are especially limited.

Solution

Fully offline TTS engine reads PDFs with real-time word highlighting; speed control, bookmarks and notes; optimized for academic papers and textbooks.

Users

Students, dyslexic readers, language learners who read PDFs

MVP

PDF parsing and text extraction; offline TTS playback; word-level highlight sync; speed adjustment; basic bookmarks

Revenue

One-time purchase with student discount; later in-app purchases for premium voice packs

Why now

Offline TTS quality has improved and device compute suffices; student market has clear privacy and offline needs