BookFusion iOS 1.43.1 – Online & Offline Realistic TTS Voices, Other Updates & Fixes

Over the past few months, we’ve been busy. Several releases have shipped, but we held off on the write-ups on purpose. We wanted to land some of these features across all three platforms before telling the full story. So here it is: a round-up of what’s new, what we fixed, and a look at what’s coming next.

Realistic Text-to-Speech (TTS) voices arrive for every reader

We’ve expanded the Text-to-Speech experience across your EPUBs, PDFs, and other formats to include realistic TTS voices, for reading and listening that finally sounds the way it should.

  Realistic TTS comes in two flavours:

• Online / Streaming:  Built on Kokoro models, with our own tweaks and refinements on top. We run our own TTS service for these, which lets us keep quality high and keep subscription prices exactly where they are. No surprise increases, no catch.
• Fully Offline / Local:  Powered by Supertonic, these voices run entirely on your device. No internet, no pre-downloading generated audio. Everything happens locally and on demand, right where you’re reading. Perfect for planes, subways, and anywhere the signal doesn’t reach.

Streaming Realistic Text-to-Speech(TTS) Voices 

Unlimited streaming of genuinely natural, human-sounding voices are now supported across  all your content in the iOS app for Advanced and Power readers.   And because nobody should commit to a voice unheard, we added Voice Previews so you can test each one before making it your default.

Fully Offline, Realistic Voices, Zero Limits – Meet Supertonic 

Then we went further. Much further. We also added support for Supertonic which  brings realistic TTS voices directly onto your device ,processed locally, no internet required, no interruptions all readers (Free, Casual, Advanced & Power)

Guide for Using Supertonic Offline TTS – https://docs.bookfusion.com/docs/text-to-speech-&-audio/offline-voices-ios 

• Unlimited streaming. No tokens. No character caps. No time restrictions.
• Download voices for true offline listening, processed right on your device. Perfect for planes, subways, and off-grid weekends.
• Noticeably higher quality  than the standard iOS voices.
• 31 languages supported fully offline:  Arabic, Bulgarian, Croatian, Czech, Danish, Dutch, English, Estonian, Finnish, French, German, Greek, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Latvian, Lithuanian, Polish, Portuguese, Romanian, Russian, Slovak, Slovenian, Spanish, Swedish, Turkish, Ukrainian, and Vietnamese.

Whether you’re a language learner, a multilingual reader, or someone who reads with their ears for accessibility reasons,  this update is for you.

Other Updates

Text-to-Speech (TTS) & Media Overlay Refinement 

Great narration is only half the story; the interface has to keep up. So we rebuilt the TTS and Media Overlay experience from the ground up for a smoother, calmer experience:

•  Choose a voice, adjust playback speed, and skip forward or back one sentence at a time.
• We rewrote our sentence tokenizer for more natural pacing and fewer clumsy breaks.
• The app now highlights each sentence as it’s spoken, so your eyes never lose their place while your ears do the work. (Only with supported voices) 
• Footnotes finally behave:*superscript footnotes are skipped during playback, and inline EPUB footnotes  now open with a single tap.

Small touches, obsessed over, until listening felt like reading again.

Find exactly what you’re after

As libraries grow, finding the right thing matters more. You can now filter your content by type: Books, Articles, or All . As a result  your saved web reads and your books each have their place, and you find exactly what you want instantly. 

*Articles added in preparation for the launch of Article support that is in beta 

Metadata updates 

Metadata is the quiet backbone of a well-kept library. You can now view and edit the Publisher and Publication date  for your books and articles. One more way to keep your collection precise, tidy, and truly yours.

Additional localizations 

This half-year we welcomed:

• Spanish  localization for the iOS app.
• Polish localization for the iOS app.

Want to see  your language supported? Reach out  to us at support@bookfusion.com  some of our best translations come from readers like you OR apply at https://bookfusion.notion.site/help-us-translate-bookfusion 

Fixes. We Fixed a Lot.

We don’t hide our bugs; we hunt them. Craftsmanship means owning the flaws as openly as the features. Between January and July, we resolved a long list of them:

Reading & rendering

• Fixed highlight positioning in certain PDFs where highlights appeared in the wrong spot.
• Fixed incorrect page sizing for some fixed-layout EPUB books.
• Corrected oversized math formulas in some books.
• Fixed text truncation in some vertical-writing books.
• Improved rendering of PDF books in Dark Mode.
• Stopped stray HTML/code from showing up in some book descriptions.
• Enforced your font settings for books that ship with their own predefined fonts.
• Fixed the empty-screen issue when opening malformed EPUB files.

Text-to-speech

• Fixed a crash during TTS playback in PDF books.
• Fixed Local TTS failing on long sentences.
• Fixed unresponsive touch when toggling the TTS overlay controls.
• Corrected the play-button state in the PDF reader.
• Restored offline mode for local voice-model previews, and added loading indicators while previews generate and after TTS starts.
• Tuned memory management for the TTS cache.

Library & everything else

• Fixed the ordering of downloaded and currently-reading books.
• Restored missing copy/paste menu items on the Highlight Notes screen.
• Fixed a crash when opening the reader for invalid PDFs with no pages.
• Fixed message input on the Highlight Discussion screen when typing in Korean.
• Improved comic-book handling to show a clear error for invalid comics.
• Made Replace Files smoother when updating existing books.
• Improved widget performance and reliability.
• Corrected several Spanish and Polish translation errors.

Noticed something still off? We genuinely want to hear it. Reach us at support@bookfusion.com

The work continues

That’s six months of steady, deliberate craft: better voices, a smarter reader, refining article support, and a great many bugs resolved. None of it happens without you, the readers who push us, report the rough edges, and remind us why we love this work.

In the next few updates we will be focused on the following:

• Wrapping up and launching articles 
• Sleep timer for both TTS & Media Overlays 
• Support page numbers (no longer only percentage)
• Custom headers and footers ( clock, battery, reading time & more) 
• Surprise! (reply with what you want the surprise to be :))

We’re just getting started. Update to the latest version, put those new voices to the test, and tell us what you think.

Happy reading (and listening),

— The BookFusion Team