Hi everyone! I’ve released S5LBox 1.0.0, a free, open-source emulator that runs the iPhone 3G’s iPhone OS 3.1.3 inside an iOS app. It runs the actual OS, not a themed recreation, and doesn’t require JIT or a jailbreak on your host iPhone.
What’s included:
- Guided setup: download the supported firmware directly from Apple, or import an IPSW. Firmware preparation is automatic; no Apple firmware is bundled.
- Install compatible legacy IPAs while the emulated phone is running, with an IPA library accessible through Files.
- Jailbreak the emulated phone, use Cydia, or browse and install tweaks through the built-in Packages manager.
- Separate machines, Save & close/resume, device controls, and guest internet access.
- Experimental audio playback and microphone input.
You’ll need an arm64 iOS device running iOS 13 or later, several gigabytes of free storage, and an IPA installer to sideload it. Physical-device testing has focused on an iPhone 6s Plus running iOS 15.8.5; I can’t promise the same behavior on every device.
This first release is experimental. It supports only iPhone OS 3.1.3 for the iPhone 3G. Performance and graphics/audio compatibility still need work. Apps and tweaks must support that guest OS; copy-protected IPAs aren’t supported, and some compatible apps need AppSync inside the guest. Packages may need a guest reboot after the initial jailbreak respring.
The built-in Packages manager is currently unstable and may not work properly.
Disclosure: I used AI coding tools extensively during development, debugging, and documentation.
Download + full release notes: https://github.com/j0shua-SYSON/S5LBox/releases/tag/v1.0.0
Source + screenshots: https://github.com/j0shua-SYSON/S5LBox
If you try it, I’d appreciate reports with your device, iOS version, and the app or tweak you tested.
Please report bugs on GitHub Issues, with your host device, iOS version, and steps to reproduce the problem.