Apps for Mazda Connect (v74) — What Runs & What Doesn't

The Gen 6 Mazda Connect CMU runs apps as HTML5/JavaScript bundles inside its built-in browser engine, rendered at 800x480 to match the screen. The same mechanism the factory uses for some of its own screens is what every third-party app hooks into. That’s why apps are possible at all — and why firmware changes break them.

This page covers what actually runs on v74.00.324A: the apps Miatafy maintains and ships, and the older community apps you’ll still find referenced around the internet but that mostly no longer load.

Why firmware version decides everything

Apps don’t talk to the CMU directly. They go through the lifecycle, data, and input interfaces the community originally reverse-engineered via CASDK and bundled through MZD-AIO. Those interfaces are part of the firmware. When Mazda changed them (and they changed several times across the Gen 6 run), apps written against the old shape stopped initializing.

The practical line: most AIO/CASDK-era apps were written for firmware before v70 and were never updated for v74. They are not “risky” on v74; they generally just don’t load. Installing the legacy AIO bundle on a v74 unit is not a supported path. If you’re on older firmware and following the original project docs, those apps may still work for you — but that’s the old world, not this one.

MFY apps (maintained for v74)

These are written and tested against v74 and installed through ScreenTune. Where one is part of a paid product, it’s noted; the rest install with any ScreenTune package.

FastData

High-rate logger that reads the CMU’s internal vehicle data bus and writes to USB. Captures speed, RPM, steering angle, and throttle position at sample rates meant for post-drive analysis rather than a live readout. You pull the file off the drive afterward and look at it on a computer.

Hotkeys (coming soon)

Remaps the center-console mute button to send CarPlay play/pause. Runs as a small background process and leaves the button’s behavior alone everywhere else — it only acts on the press when CarPlay is the active source. Still in development, not part of a shipping package yet.

Gauges (coming soon)

Renders live gauges on the screen: a G-force scatter plot and speed trace in track mode, a speedometer and simple gauges in street mode. Built as an 800x480 web app for the CMU browser, with Commander-knob navigation. Gauges is an upcoming ScreenTune capability, not part of the current build.

On accuracy: the CMU’s motion data comes from a chassis-mounted sensor, not a phone on a mount. See g-force accuracy for what that does and doesn’t get you versus a dedicated logger.

GPS Speed (coming soon)

Speed display driven by the CMU’s own GPS receiver rather than the wheel-speed sensor. Useful as a second reference or for sanity-checking speedometer calibration, since the two readings come from different sources.

Community apps (legacy, pre-v74)

These came out of the MZD-AIO/CASDK era. They are not included in, tested with, or supported by ScreenTune, and most were last built against firmware that predates v74. Treat them as historical unless someone has published a current v74-specific port.

App	What it does	v74 status
Speedometer	Large digital speed readout on the screen	Legacy AIO build; do not install on v74
Video Player	Plays USB video files on the CMU display	Needs the swapfile tweak to avoid out-of-memory crashes; legacy
CastScreen Receiver	Mirrors a phone’s screen to the CMU over Wi-Fi	Legacy
Vehicle Data Display (VDD)	On-screen view of RPM, coolant temp, throttle, etc.	Legacy
MultiDash / Simple Dashboard	Replacement home-screen layouts (multi-widget or minimal)	Legacy
Android Auto Headunit	Renders Android Auto on the CMU display	Pre-v70 only — later firmware changed the interfaces it depends on

The Video Player point generalizes: the CMU has very little RAM, and anything decoding media wants swap space it doesn’t have by default. That’s why the legacy Video Player paired with a swapfile tweak, and why memory-hungry ports are the first to fall over on a stock unit.