Tracker Detector: Hidden Tags

See what is transmitting around you: tracking tags, Bluetooth gadgets and Wi-Fi access points. Check a hotel room in 90 seconds, or let the app notice a tag that travels with you.

ANTI-SPY SCANNER is a hidden device detector that listens on four radio channels at once and names each device in plain words.

Tracker detector
Apple Find My tags such as AirTag, Google Find My Device tags and Tile use a published format, so the app marks them as trackers at once. Samsung tags are marked as possible, because other Samsung accessories send the same signal.

Room check
Keep the screen on. For 30 seconds the app measures the room's usual background, then listens for another 60. You get three numbers: devices seen, how many are yours and how many are louder than the background, plus one sentence on what that means, ready to share.

Inspection checklist
Then tick off eight places where cameras are usually hidden, each with the tool that helps there. The ticks are your own marks: the app keeps count and never calls a place clear.

Hunt for a tag that follows you
A stranger's tag gives itself away by staying with you, while a neighbour's router falls behind. The hunt flags a device heard for more than 8 minutes in at least three places while you travel over 250 metres, and keeps watching with the screen off. A flagged device shows its trail: where your phone first heard it, and how long and how far it travelled with you. Mark your own earbuds as "Mine" to take them off the hunt.

Radar
Pick a device, turn slowly on the spot, then walk. A ping speeds up as you get closer, so you can search without looking.

Map
Every measurement lands on an OpenStreetMap coverage map, one colour per channel. A device heard from four places or more gets an estimated position.

Hidden camera search
Sweep a shelf in magnet mode and listen: the clicks speed up as the field jumps, and a 20-second trace shows where. Speakers, wiring and steel move the field too, so a jump means look here, not camera found. In the dark the viewfinder shows a night-vision camera's infrared light as pale violet dots, and the torch shows a lens glint.

Four channels in one list
• Bluetooth LE: tags, watches, earbuds and sensors.
• Bluetooth pairing mode: headsets and speakers waiting to connect.
• Wi-Fi: access points with band, channel and security.
• Cellular: the serving tower and its neighbours, 2G to 5G.

A built-in reference names common signals: tyre pressure sensor, TV, printer, phone hotspot, camera with its own Wi-Fi network. A bug or other hidden device shows up only if it broadcasts over Bluetooth or runs its own Wi-Fi.

Good to know
This is a radio scanner around the phone, not a check of the phone for spyware. Cameras are searched for indirectly, and no technique is proof. The app cannot find a camera that records to a memory card, a wired microphone or a GPS tracker that reports over the mobile network. Wi-Fi shows access points only, so a camera on the hotel's own network does not appear.

Distance and direction are estimates. Wi-Fi rows refresh about every 30 seconds, as often as Android allows. Devices with a private address change it about every 15 minutes, so a "Mine" mark does not last. A device on the list is not proof that anyone is watching: neighbours have speakers, and parked cars have tyre sensors. The screenshots show the built-in demo.

Privacy
Android gives Bluetooth and Wi-Fi scan results only with location access. Coordinates draw your map and stay on the phone. The network is used for OpenStreetMap tiles of the area you view, a check for a newer version and, only if you switch them on, anonymous usage statistics. Scan results are never sent anywhere.

Interface in English, Polish and Russian: the phone's language or the one you pick in settings.

Independent development: one person builds and maintains this app. A letter to support@markarov.dev is read by that person, not by a support desk.

Recent changes:
The live list is calmer and clearer: channel filters are quiet capsules with a coloured dot, Live/Mine sits in the same row, and the button says what it does and for how long — "Listen 60 s". When a pass ends, the top shows "Scan paused · List as of 09:38" with Resume, and the list is muted, so old readings are never mistaken for live ones. If the magnetic background is above Earth's field (over 75 µT), the magnet screen offers to zero it.