Tandem Books vs StoryCodex

Read your book. Listen to it. Switch back and forth without losing your place. Tandem pairs your ebooks with your audiobooks. Start a chapter with your eyes on the train, tap once to continue with your ears on the walk home. Your place follows you between reading and listening. BRING YOUR OWN FILES No bookstore lock-in. Import any DRM-free EPUB ebook and pair it with a matching M4B or MP3 audiobook. Tandem works with files you already own. SWITCH WITHOUT LOSING YOUR PLACE Tap once to switch from reading to listening, or the other way. Tandem uses short audio transcription to line up the ebook and audiobook, then remembers those positions on your device so repeated handoffs in the same area are faster. MADE FOR READING A warm paper surface with a beautiful serif typeface. Adjustable size and spacing. Full-screen immersive mode hides every distraction so you can stay with the book. ONE UNIVERSAL APP Buy once, use it on iPhone, iPad, and Mac. Built natively for Apple platforms using SwiftUI. PRIVACY FIRST No account required. No sign-up. No analytics. Your books live on your device. The only time Tandem ever touches the network is a brief audio transcription when you switch modes — and even that data is never stored. FEATURES • Paired ebook + audiobook in one app • Reading and listening stay aligned as you switch • Warm Paper and Night reading themes • Adjustable text size and line spacing • Per-book reading progress saved automatically • Full keyboard shortcut support on Mac • No account. No subscription. No cloud storage of your books. REQUIREMENTS iOS 26, iPadOS 26, or macOS 26. Bring your own DRM-free EPUB ebooks and M4B or MP3 audiobooks. Kindle, Audible, and other DRM-protected files are not supported.

You're on chapter 600. A name appears you half-remember. The wiki would spoil everything. StoryCodex is a smart novel reader that builds a live encyclopedia and visual Story Map of your story as you read. It tracks your progress and only remembers the events you have already reached. Stop choosing between losing track of the plot and getting spoiled by fandom wikis. LISTEN OR READ ANYWHERE Experience a polished core reading environment. Listen to your chapters aloud with high-fidelity neural voices including Supertonic, Kokoro, and Piper. Background playback, lock screen controls, and customizable reading views. No internet connection required. TAP ANY NAME, SEE WHO THEY ARE Tap a character name while reading to instantly view their profile: role, traits, power tier, and key relationships. Pulled strictly from chapters you have already read. Zero spoilers. No wiki rabbit holes. EXPLORE THE STORY MAP See characters, factions, places, and relationships as an interactive visual map. Follow alliances, rivalries, mentors, clans, sects, and shifting connections without exposing future events. The Story Map grows with your reading progress, so it stays useful and spoiler-free. YOUR STORY CODEX As you read, the local AI silently builds and updates your universe. Character profiles track names, aliases, motivations, and power progression. World building maps places, factions, cultivation systems, and items. Arc summaries break the full story into arcs, always spoiler-free. Chapter summaries log every chapter so nothing slips through. The codex carries across volumes, so your encyclopedia grows with the series. PICK UP EXACTLY WHERE YOU LEFT OFF Tap Previously before any chapter for an instant recap: the last few key events and a summary of recent chapters. Like a previously on for your novel. No reread, no spoilers, just back in the story in seconds. LOAD EPUBS OR WEB CHAPTERS Import web novels and light novels via EPUB, PDF, or plain text. Reading a multi-volume series? Save each EPUB as a volume under one series and share the same codex across all books. Paste a chapter URL from any public novel site to start reading and listening instantly. The built-in reader strips ads and clutter for a distraction-free experience. 100% ON-DEVICE. COMPLETELY PRIVATE. Your library and chapters never leave your phone. Local AI handles all analysis. No account, no external servers, no subscription required for core features. STORYCODEX PRO, OPTIONAL AND ONE-TIME For readers who go deep. Unlock advanced world-building analysis and the full interactive visual Story Map. One-time purchase, no recurring fees. Built for web novels, light novels, xianxia, LitRPG, and massive fantasy epics. Requires 6GB RAM or more for local AI models. Pro users on cloud AI have no device requirements. PERFECT FOR: • LitRPG, progression fantasy, cultivation/xianxia, isekai • Epic fantasy with huge casts (noble houses, guilds, sects) • Multi-volume series you read over months or years • Readers who take breaks and need quick recaps