IO reader: Books in Reels

IO Reader presents reading in smaller, focused units instead of a long continuous page. Its Reel view shows one paragraph at a time in a vertical flow, while Cards moves through a chapter sentence by sentence. Readers can save passages and notes in a Keepsake Box, and the app describes an AI that responds to passages with questions intended to prompt reflection. IO supports reading offline and offers account-based personalization and syncing across devices. The free experience includes the core reading format, while IO+ adds unlimited AI personas, AI-powered search and recommendations, and cross-device sync through a monthly or annual subscription. The listing does not give current subscription prices. Readers should check the source and format requirements for adding books, since the app's description focuses more on the reading interface and AI features than on catalog availability.