LinkJig Privacy Policy
Last updated: 14 October 2026
LinkJig is a tool for talking to your own hardware over USB serial, USB HID, Bluetooth Low Energy and TCP, and for turning that into repeatable tests. This policy explains what the app does with data on Android and Windows.
Short version: LinkJig has no account, no analytics and no server of its own. The tool itself never shows ads. On Android, the optional Start Bit mini game shows ads from Google AdMob; nothing ad-related runs until you open the game (see "Ads"). The desktop app contains no ads. Everything else LinkJig stores stays on your device, nothing is sent anywhere unless you send it yourself, and the app goes online only for checks you start (see "Online checks you start").
What the app stores on your device
- Settings — theme, terminal options, macros, triggers, scenarios and send history.
- Recent devices — names and identifiers of devices you connected to (for example a COM port name, a Bluetooth address or a host and port), so they can be reopened from the Devices screen, and the connection profiles you save.
- Wi-Fi passwords — only for networks you tell LinkJig to remember. On Android they are encrypted with a key kept in the Android Keystore and are left out of backups; on Windows they are kept in the system's Wi-Fi profile, like any network you join. They are never put in project packs, shortcuts or diagnostic reports.
- Logs and snapshots — only when you save a log, turn on automatic session logs, or a trigger takes a snapshot. On Windows they are in
Documents\LinkJig; on Android they are in the app's private storage. - Game and reward progress (Android) — Start Bit levels, ad counters and whether Pro and themes are unlocked, in one encrypted file. Because there is no account, this one file is included in Android's backup to your Google account, so Pro is not lost when you reinstall or change phones. Nothing else LinkJig stores is backed up.
This data never leaves your device through LinkJig, apart from the backup above. Uninstalling the app (or clearing its storage on Android) deletes it, except files you saved elsewhere.
What the app sends
- Data to your devices. Bytes you type, macros, files you choose to send, scenario steps and trigger replies go to the device or network address you connected to — nowhere else.
- Network. LinkJig opens a network connection only to the host and port you enter or pick. It does not contact any server of its own.
- Finding devices on your network. Only when you tap "Find" on the Network screen, LinkJig sends standard mDNS queries (the same kind printers and smart speakers use) to your local network and lists the devices that answer. These queries do not leave your local network and nothing is stored except the connections you then open.
- Wi-Fi. LinkJig lists nearby Wi-Fi networks only when you tap "Scan" on the Network screen, and joins only the network you pick, so a TCP connection can reach a device's own access point. On Android 10 and newer only LinkJig uses that network and the rest of the phone stays online; on Windows and older Android versions the device switches networks until you leave it.
- Sharing. When you share a log, a scenario result or a project pack, the file goes to the app you pick in the share sheet. LinkJig does not see what happens after that.
- Diagnostic report. "Copy diagnostic report" puts a text on your clipboard so you can paste it into a support request. It contains the app version, the operating system, the phone model (Android), the permission states and the connection settings. It contains no terminal data, serial numbers, Bluetooth addresses or IP addresses. It is not sent anywhere by the app.
- Online checks you start. A few buttons fetch public files from GitHub, which hosts the LinkJig website. Each runs only when you tap it and sends nothing but an ordinary web request; as with any website, GitHub sees your IP address (see GitHub's privacy statement).
- Pack library. "Check for new packs" downloads the signed pack list; opening a pack that is not built into the app downloads that pack.
- Updates (Windows). "Check for updates" in Settings reads the latest version number.
- Desktop Pro (Windows). "Enter code" reads the current time from github.com once, so the code's validity period can be checked. The code itself is not sent.
- Links. This policy, the FAQ and "Suggest a pack for the library…" open in your web browser.
Ads (Android, Start Bit mini game only)
The terminal, devices, connections, scenarios, macros, triggers, logs, library, settings and help never show ads. Ads appear only inside the optional Start Bit mini game: a banner on the game's menu and result screens, and short video ads that you choose to watch for a reward (Pro progress, a theme, an extra life, a code for the desktop app). There are no ads while you play, no ads when the app starts and no ads in notifications.
- Who. Ads come from Google AdMob (Google Mobile Ads SDK). The SDK is not started until you open the game; if you never open it, nothing ad-related runs.
- Consent. In the EEA, the UK and Switzerland, Google's consent message is shown the first time you open the game, before any ad is requested. You can change your choice at any time in Settings → Privacy → "Ad privacy choices" (also in the game's menu) where this applies.
- What AdMob collects. IP address (used for approximate location), app interactions with ads, diagnostics, and device and advertising identifiers. The data is encrypted in transit. Google's use is described at https://policies.google.com/technologies/partner-sites.
- Advertising ID. You can reset or delete it in Android settings (Google → Ads, or Privacy → Ads, depending on the phone).
- Never shared with ads. Terminal data, device names, logs, scenarios and Wi-Fi passwords are never given to the ad SDK.
The desktop app contains no ads.
Android permissions
| Permission | Why |
|---|---|
| Nearby devices (Bluetooth scan / connect) | Find and connect to Bluetooth devices you choose. Scanning is not used to determine your location. |
| Location | Android requires it to list Wi-Fi networks (every version) and for any Bluetooth scan (up to Android 11). LinkJig does not read your location. |
| USB devices | Talk to USB-serial adapters and USB HID devices. Android asks you for each device. |
| Internet / network state | TCP connections to the address you enter; ads in the optional mini game. |
| Advertising ID | Used by Google AdMob for ads in the optional mini game. You can reset or delete it in Android settings. |
| Wi-Fi multicast | Receive answers to "Find" on the Network screen (mDNS); held only while the search runs. |
| Notifications and foreground service | Keep an open connection running while the app is in the background, with a visible notification. |
| Nearby Wi-Fi devices (Android 13 and newer) | List Wi-Fi networks when you tap "Scan". Not used to determine your location. |
| Wi-Fi state / change Wi-Fi | Join the device access point you pick. |
On Windows 11, Windows shows Wi-Fi networks to apps only while location access is allowed for apps. LinkJig asks for it only so the Wi-Fi list works; it never reads your location.
Children
LinkJig is a developer tool and is not directed at children. Its store listing is for adults, and ads in the mini game are requested without child or teen treatment.
Purchases
LinkJig sells nothing and has no in-app purchases. Pro is free: on Android it unlocks by reaching level 15 in Start Bit or by watching a few short ads; on Windows it is activated with a free code made in the Android app.
Changes
If this policy changes, the new version will be published at the same address with a new date. If LinkJig ever adds crash reporting, it will be off by default, ask for your consent first and never include terminal data.
Contact
Questions: linkjig.app@gmail.com