Privacy Policy

Effective date: September 14, 2026 · HotWire CNC for Android

The short version: this app does not collect, store, or transmit any of your personal data, anywhere, ever. Everything it does happens locally, on your phone and on your local Wi-Fi network.

What the app does

• Talks to your CNC controller board over a wired USB connection (USB Host API), sending and receiving G-code and machine-status data directly to and from the board. This never leaves the USB cable.

• Optionally runs a small local web server on your phone's Wi-Fi network so a computer on the same network can upload a G-code file to the app (it automatically searches for a free port on your own phone if the default one is busy). This server is only reachable from devices on your own local network — nothing is sent over the internet.

• Stores G-code files you load or upload in the app's private storage on your phone. You can also save a file to a location of your choosing (edited, reversed, or as loaded) using Android's own file picker — the app never requests broad storage access; you choose the exact folder and filename each time through the system picker.

• Stores your settings (units, feed rates, jog presets, connection behavior, and similar preferences) locally on your phone, so they're there the next time you open the app.

What the app does NOT do

• It does not collect personal information (name, email, location, contacts, photos, etc.).

• It does not use analytics, crash-reporting, or advertising SDKs of any kind.

• It does not create accounts or require you to sign in.

• It does not transmit any data to the developer or to any third party.

• It does not share data with third parties, because it doesn't collect any to share.

Permissions the app requests, and why

Permission

Why it's needed

USB Host

To communicate with the grblHAL controller board over USB.

Internet

Required by Android to open a local server socket for the Wi-Fi file-upload feature — no data is sent over the public internet.

Foreground service (connected device)

Keeps the USB connection and a running cutting job alive if you switch apps, take a call, or the screen turns off.

Notifications

Shows the ongoing connection/job status notification while the app runs in the background.

Wake lock

Keeps the phone's CPU from sleeping while a cutting job is actively running, so it doesn't stall partway through.

None of these permissions are used to collect or transmit data about you — they exist solely to let the app talk to your hardware reliably.

Data storage and deletion

All data the app stores (G-code files, settings) lives in the app's private storage on your phone. Uninstalling the app deletes all of it. There is no cloud backup, account, or server-side copy anywhere.

Children's privacy

This app is a hobbyist/professional CNC machine-control tool. It does not knowingly collect information from anyone, of any age, because it does not collect information at all.

Changes to this policy

If this app's data practices ever change, this policy will be updated here and the "Effective date" above will reflect the change. Given the app's purpose and design, no such change is currently planned.

Contact

Questions about this policy can be directed to the developer through the app's listing page on Google Play or droidforks@gmail.com.

HotWire CNC — Android controller for grblHAL-based hot-wire CNC cutters.