Hebrish on iPhone: what it would take
A friend asked whether Hebrish could run on an iPhone. The short answer is yes. The model files the Android app uses already work on iOS. What changes is how the app fits into the phone, and how people install it. This post lists what a first iPhone version needs and what it would cost. It is on the projects board as under consideration.
The model already fits
The Hebrish apps run the model with sherpa-onnx, using the int8 files on Hugging Face (about 660 MB). sherpa-onnx has an official iOS build with a Swift interface, and those same files load on it. So v1.0 (checkpoint 6) needs no new export for iPhone. Like the other apps, the iPhone app would download the model once and then work offline. Audio stays on the phone.
The model needs more than a gigabyte of memory once it is loaded. Recent iPhones have that to spare in a normal app. How it does on older phones is one of the things to test.
No voice keyboard, and why
On Android, Hebrish is a voice keyboard: you dictate straight into any app. iPhone can't do that. Apple does not let custom keyboards use the microphone, and it limits their memory to far less than a speech model needs.
So the iPhone version is an app. You open it (or trigger it from Shortcuts or the Action Button), speak, and the text is copied, ready to paste. Later, a keyboard could hand off to the app to record and then paste the text back. Some dictation apps for iPhone already work this way. That is a second step, not part of the first version.
Installing it: TestFlight, not sideloading
On Android you can download an APK and install it. iPhone has no equivalent for ordinary users. An app built at home and signed with a free Apple account runs only on its developer's own phones and stops working after seven days. That is fine for our own testing, but not for anyone else.
For a version anyone can install, the route is TestFlight, Apple's beta-testing app. It needs a paid Apple Developer Program membership. One public link lets up to 10,000 people install the app. Apple reviews a beta lightly before the link works, and each build runs for 90 days, so new builds go out regularly. The App Store can come later, with the same membership.
The tasks
The first sprint, from nothing to a public TestFlight link:
- Join the Apple Developer Program and set up the app's identity and signing.
- Set up a Mac build. iPhone apps can only be built and signed on macOS, either on a Mac or on a hosted macOS build service.
- Build the app in SwiftUI on the sherpa-onnx iOS library. The app logic follows the Android app's shared engine.
- One-time model download from Hugging Face, with progress shown, resuming if interrupted, and stored on the phone.
- Record, transcribe, copy: a microphone button, transcription on the phone, and the text copied for pasting or sharing.
- Shortcuts and the Action Button, so dictation starts without hunting for the app.
- Test on real iPhones, older and newer: memory, speed, battery and accuracy against the Android app on the same clips.
- Submit for beta review and publish the public TestFlight link.
- Add iPhone to the download page and the changelog.
Later, not in this sprint: the keyboard hand-off described above, and an App Store listing.
What it costs
| Item | Cost |
|---|---|
| Apple Developer Program membership (needed for TestFlight and the App Store) | $99 a year |
| Time: building, testing and keeping it running. A token amount; the work is mostly volunteered | $100 |
| Testing and build resources: hosted Mac builds, and access to older iPhones for testing | to be costed |
| Total to start | about $199, plus testing |
The membership renews every year, so keeping the app installable costs $99 a year after the first.
How to help
Donations are not open yet. When they are, this project's goal will appear on the projects board and the support page, so it is clear what the money pays for. In the meantime, if you have an iPhone and would test an early build, get in touch.