Blog
Offline text to speech, written down
Guides and audits on reading EPUB, PDF and web articles aloud on an iPhone: what the Kokoro-82M model is and how it runs on Apple MLX, which apps on the App Store actually use it, and what the word “free” turns out to mean once you read the in-app purchase list.
Posts
· 16 min read
Every Kokoro TTS app on the iPhone App Store
Nine iPhone apps run Kokoro-82M on the device, not three. Prices, downloads, device floors and honest limits, read off every App Store listing.
· 9 min read
Free iPhone text to speech, and where free stops
Five ways a free iPhone text-to-speech app stops being free — characters, hours, voices, books and the turnstile — with every figure and its source.
· 9 min read
Neural text to speech on older iPhones: what each app asks for
Three gates decide whether a neural reader installs on an older iPhone: the iOS version, the chip and the memory. What each app asks for, and why.
· 10 min read
How Kokoro-82M runs on an iPhone with Apple MLX
Kokoro-82M runs on the Apple silicon GPU through MLX — not the Neural Engine, not Core ML. The pipeline stage by stage, and what that choice costs.
What this blog is for, and what it will not cover
Sandbook is one app made by one person, so this blog is not going to out-publish a content team, and it is not going to try. The rule here is that a post has to carry something the reader cannot get from a listicle: a figure read off a named source on a named day, a table with every candidate in it rather than the three that flatter us, or an explanation of how the thing actually works.
That rule also rules things out. You will not find a post here about listening to a whole book with your phone in your pocket on the commute, or about turning a book into an MP3 audiobook, because Sandbook does neither of those things. An app blog that writes for search intents its app cannot serve is buying a bounce.
The product pages are the other half of this site: the Kokoro TTS app for how the model runs on the device, free text to speech for what is and is not charged for, the 41 voices to hear them, Kokoro TTS online to try the model on your own text in a browser, and the alternatives page for how Sandbook sits against the paid readers.
There are no category pages here on purpose. When a subject earns more than a handful of posts it will get a real hub page with a real introduction, not an automatically generated shell.