Cellular, GPS and Bluetooth
See which mobile cell you're on
“Cellular” shows the mobile network as the phone's modem reports it. It needs location and phone-state access: Android shows cell details only to apps with both. It follows the SIM used for mobile data.
- The top shows the operator, network type and signal. With carrier aggregation it lists the carriers being combined and their widths.
- “Serving cell” shows the cell's identity: MCC-MNC (country and network), TAC (area), eNB / sector or gNB / cell (the base station and which of its antennas serves you), PCI, the channel number with its band and frequency, bandwidth, and timing advance.
- “Base station” estimates your distance from the mast from the timing advance (about 78 m per step on LTE). The modem only reports it while transmitting, and some always report 0.
- “Neighbor cells” lists the other cells the modem hears. Many modems list neighbors only while idle.
- “Serving cell signal (RSRP)” charts the last 10 minutes; vertical lines mark a change of serving cell.
Android refreshes cell data every 2 to 10 seconds, and the screen says how old the reading is. Values the modem doesn't report show as “–”. GSM and WCDMA cells aren't shown.
Read the signal bars
Each signal value has a bar, colored from green (good) to red (poor). On LTE:
| Value | What it measures | How the app colors it |
|---|---|---|
| RSRP | How strong the cell's signal is, in dBm. | −90 or better · to −100 · to −110 · below −110 |
| RSRQ | Signal quality, in dB: how much of what arrives is this cell rather than load and interference. | −10 or better · to −15 · to −20 · below −20 |
| SINR | Signal against noise and interference, in dB. Higher is better. | 20 or more · 10 or more · 0 or more · below 0 |
5G that shows in the status bar but not here
Many phones show “5G” while actually connected to LTE with 5G added on top (5G NSA). In that mode many modems don't report the 5G cell to apps. The screen says so rather than hiding it: “5G (NR) signal” shows the 5G signal values when reported, and otherwise it points to the aggregated carriers above.
Find where a cell's mast is
Mobile cells don't broadcast their position. Tap “Look up site location” to ask beaconDB, an open crowd-sourced location database, for the selected cell. Only the cell's identity is sent, not your position. A result opens in your map app. It's a crowd-sourced estimate, not the surveyed mast position, and many cells aren't known.
Survey cells along a route
The “Cell survey” panel logs every cell the modem reports, together with your GPS position, while you walk or drive. Cells are grouped into sites (base stations), and each site is roughly placed where its signal was strongest. The position leans toward the route you took, so treat it as a rough guide. Tap “Start survey”; “Export” saves a CSV of every reading or a Markdown summary. The screen stays on while recording. Pro
Spot fake base stations (cell watch)
Fake base stations (“IMSI catchers”) pretend to be a normal mobile cell. “Cell watch” learns which cells normally serve you, by place, and scores each new serving cell for warning signs: a drop to 2G with good LTE or 5G signal, area codes or channels that don't fit, a known cell that moved far away, unusual strength, or no neighbors. Each verdict, “Normal”, “Unusual” or “Suspicious”, lists its clues with their points. Pro
- “Alert log” lists past non-normal verdicts. Cells used once, for under 5 minutes, and never again are listed as “used only briefly”: a short fake-station run, or just a cell at the edge of your route.
- “Watch in the background” keeps checking the serving cell once a minute with the app closed, with a notification while it runs.
- These are indications, not proof. The clearest signs, such as encryption being switched off, aren't visible to apps without root.
The free version still warns about a drop to 2G.
Check GPS and the time
“GPS” shows the satellites the phone hears, your position and how accurate it is, and how the phone's clock compares with GPS and network time. It needs location access and location services switched on.
- “Here” shows the coordinates with their accuracy (±), altitude, speed and heading, and how long the first fix took. Tap the coordinates to open them in your map app.
- “Sky” draws every satellite where it is in the sky, and “Satellites” lists each one's system, signal strength (C/N0), elevation, band and whether it's used in the fix.
- C/N0 is in dB-Hz: above 35 is strong, below 20 barely usable. Indoors the signal is often too weak for a fix; try a window or go outside.
- “Dual frequency” (L1 + L5) means the phone also uses the newer L5 signals, which are more accurate near buildings.
“Time” compares the phone's clock with GPS time (needs a fix) and Android's network time (Android 13 and later). The offset is phone clock minus source, so + means the phone is ahead. The time the mobile network sends is hidden from apps.
See Bluetooth devices nearby
“Bluetooth” lists the Bluetooth Low Energy devices advertising around you, while the screen is open: name, kind (for example headphones, watch or tracker), maker, address and signal. “Named only” hides devices without a name. Devices not heard for 90 seconds drop off. The list re-sorts every few seconds rather than on every update, so rows don't jump under your finger.
Many devices change their address about every 15 minutes for privacy, so the same device can appear twice. Bluetooth shares 2.4 GHz with Wi-Fi: lots of active devices nearby can slow 2.4 GHz networks.
On Android 12 and later the scan uses the “Nearby Bluetooth devices” permission and no location; Android then hides some beacons. On Android 11, Bluetooth scanning needs location access.
Find a device by its signal
Tap a device to follow it: a large, smoothed signal reading, “getting closer” or “getting farther”, and the last minute as a line. Walk around; the number rises as you get closer. It's signal, not distance: a wall or your own body can cost 10 dB. Turn slowly, since the number is highest facing the device. Pro
Spot a tracker that follows you
The scanner recognizes common location trackers (Apple Find My, Google's network, Samsung SmartTag, Tile, Chipolo and others using the shared tracker standard) and says how many are nearby and whether one is away from its owner.
With Pro, tracker watch flags a tracker that is away from its owner and has been heard over 30 minutes or more in different surroundings, so it seems to move with you. “Different surroundings” means a different Wi-Fi access point; no position is recorded. Sightings are kept for 24 hours. Tracker watch also runs in the background while one of the background services is on (the long-term roaming log, or the cell or twin watch in the background), and then notifies you if a tracker may be following you.
See what your phone's Bluetooth supports
“This phone” lists what your phone's Bluetooth can do: LE Audio, Auracast broadcast, 2M mode, long range, extended and periodic advertising, and filtering in the chip. Android doesn't report the Bluetooth version, so the app shows the lowest version those features prove. Useful when earbuds or a speaker underperform: LE Audio and 2M mode need support at both ends.