Web & mobile

Audiobook app development: reading and listening as one product

UnderBooks is a reading-and-listening platform developed by Logics7. A note on what a dual-mode product has to get right: catalogue, sync, audio delivery and retention.

UnderBooks — a reading-and-listening platform developed by Logics7. This note describes the product logic behind it and makes no claims about audience or catalogue size.

Denis Chubrenko · Head of MarketingAugust 1, 2023

Key points

Audiobook app development with a reading mode is two products joined by one shared place in the book.
In UnderBooks, reading and listening share one place, with progress synced across devices.
Rights, format economics and retention must be settled before the first sprint.

Audiobook app development changes character the moment the same book must also be read on screen. It stops being one app with an audio button. It becomes two products, text and audio, that have to agree on one thing: where the person is in the book. UnderBooks, a reading-and-listening platform developed by Logics7, is built around that single shared place.

This note sets out the product logic behind it: what each mode needs, how switching works, and which decisions have to be settled before anyone writes code. It makes no claims about audience or catalogue size.

What UnderBooks is

UnderBooks is a platform for books in two modes: reading on screen and listening, with the ability to switch between them without losing the place. It is designed for smartphone, tablet and desktop. It keeps progress in sync across devices, supports offline access for downloaded titles, and recommends what to read or listen to next based on what a person has already chosen.

In the terms most audiobook app development briefs use, it is an ebook and audiobook app, not an audiobook app with a reader attached. That distinction shapes every decision below.

Audiobook app development: two products inside one

Reading and listening look like one feature and are two different products. Text needs typography, search, annotation and fast rendering. Audio needs streaming, buffering, background playback and a position that survives a phone call. What follows is the logic of each mode in any product of this kind. It is not a feature list of UnderBooks.

Reading: EPUB, typography, offline

Ebook reader app development starts with the format. The open standard for ebooks is EPUB, now in its third major version, EPUB 3. An EPUB reader has to reflow text for each screen, from a phone to a desktop window. Typography is not decoration here: line length, font size, margins and contrast decide whether a person reads for an hour or closes the app. Search and annotation, including highlights, notes and bookmarks, must stay attached to the right passage when the text reflows. Offline access means the book, its fonts and the reader's annotations are on the device before the connection drops.

Listening: streaming, chapters, speed, background play

Audiobook streaming is a delivery problem before it is a player problem. Long recordings are usually served in segments through a CDN, so playback starts quickly and buffers ahead on a weak connection. Listeners treat chapter navigation, playback speed, bookmarks and a sleep timer as the baseline of any audiobook app. Background playback is where mobile engineering shows: the operating system can pause or stop audio at any moment, and iOS and Android set different rules. The position has to survive a phone call, a locked screen and a lost signal.

Switching between reading and listening without losing your place

The unifying logic is a single place in the book that both modes share. Getting that right is the difference between an app with an audio button and a product people actually switch modes in. In UnderBooks, a person can move from the text to the audio, or from one device to another, and continue from the same place.

01Read on one deviceReading on screen: smartphone, tablet or desktop.
02Switch to listeningThe audio continues from the place the reading stopped.
03Change deviceProgress is kept in sync across devices.
04Resume the same placeRead or listen on; both modes share one position.

Read-and-listen continuity in UnderBooks: one position in the book, shared by reading and listening and kept in sync across devices.

The hard part is invisible. A position in text is a location in the book; a position in audio is a time in a recording. Read and listen sync means mapping one to the other for every title, and it only holds when the text and the recording are the same edition. In audiobook app development this mapping is part of the catalogue work, not a player setting.

Dual-mode reading is no longer a niche idea. Amazon has offered Whispersync for Voice for years: a reader switches between a Kindle ebook and its Audible narration without losing their place. Anyone who plans to build an app like Audible should expect readers to ask for the same continuity.

Reading, listening and the synced layer compared: what each needs, and what UnderBooks provides as described in this note.
Mode	What it needs	In UnderBooks
Reading	Typography, search, annotation and fast rendering	Books read on screen on smartphone, tablet or desktop
Listening	Streaming, buffering, background playback, a position that survives a phone call	A listening mode alongside on-screen reading
Synced	One place in the book that both modes share	Switching without losing the place; progress synced across devices

Reading, listening and the synced layer compared: what each needs, and what UnderBooks provides as described in this note.

What decides whether it works: catalogue, rights, delivery, retention

For a content platform, product logic starts outside the code, and audiobook app development is no exception. The questions below are product decisions, not engineering ones, and they have to be settled before the first sprint. This is what “no development without product logic” means in practice.

Catalogue and rights

Rights and catalogue come first: what can be offered, where, on which terms, and how that is tracked. Content licensing for text and for audio is often negotiated separately, with different rights holders and publishers, so a title can exist in one mode and not the other. Catalogue metadata has to record which edition, territory and format each licence covers. If AI narration or text-to-speech is considered, whether a licence permits it is a question for the rights holder and a lawyer. DRM for ebooks and audiobooks follows from these terms: it is a licensing requirement expressed in code.

Audio delivery belongs in the same conversation. Long recordings, streamed and downloaded, make storage and CDN traffic a running cost that the pricing model has to carry.

Format economics and retention

Next comes the economics of the format: subscription, per-title or a mix, and the retention each of them requires. A subscription earns only while people keep reading or listening, so reading app retention is the business model, not a metric beside it. Credits and per-title sales depend on the next purchase, and in-app purchases through mobile app stores add their own fees and rules. Continuity between modes and recommendations based on what a person has already chosen are retention mechanics, not extras.

Accessibility closes the list. For some people listening is not a convenience but the only way in. A product that treats audio as an add-on fails them first.

What this model can be built for

The same structure serves any content or media product, not only audiobook app development: learning platforms with text and audio, corporate knowledge libraries, subscription media apps, children's content with family controls. Logics7 builds these with the mobile-grade engineering it brings from games and real-time systems (background playback, offline tolerance, sync) and operates them after launch.

For a new product, the route is a Product Partnership: we check the market, the paying user and the monetisation logic before any development is discussed. For a live reading or audio product with users whose growth has stalled, an Existing Product Review is how Logics7 decides whether to take a stake. Both routes end in a decision at the Leadership Gate, set out in how our process works.

If you are working on a content or media product, start with the right route.

Questions readers ask

How does ebook–audiobook sync work?

Both modes share one position in the book. When a person switches from text to audio, listening continues from the place the reading stopped, and the other way round. That needs a map between locations in the text and times in the recording, built for the same edition. In UnderBooks, progress is also kept in sync across devices.

What content rights does an audiobook app need?

Rights for each format it offers, in each territory, on terms it can track. Ebook and audiobook rights are often licensed separately, sometimes from different rights holders, and synthetic narration may need its own permission. Settle this with publishers and a lawyer before development: it decides the catalogue, the DRM and the release plan. This is not legal advice.

Subscription or credits: which model fits?

Neither by default: the catalogue rights and the retention you can expect decide it. A subscription needs people to keep reading or listening every month; credits and per-title sales need a reason to buy the next book. A mix is possible. Choose before the first sprint, because the model shapes the catalogue, the recommendations and the app-store payment flow.

Which route fits you?Start a conversation

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