Technical documentation

How Findy works

Five inspection methods and what each one physically measures. If you only read one page about this app, read this one.

DocumentedYes
Controlled test completedNot yet
Independent reviewNot yet
Applies to app version2.3

A. Camera lens-reflection inspection

Camera lenses reflect directed light. When you shine a light at an object and view it from close to the light's axis, a lens can appear as a small, distinctly bright point that shifts as you move. This is the same technique used to spot lenses by eye; the phone camera makes the reflection easier to notice and hold steady.

A light beside the phone reflects off a lens and returns along nearly the same path, visible only when viewed close to the light's axis.
A lens returns light along nearly the same path — so it only flares when your eye is near the light.

How Findy reports the result

3 reflection(s)

The automatic lens scan reports how many reflective points it is currently tracking and offers an Inspect action. It does not classify any of them.

B. Infrared-style viewing

Many cameras with night vision illuminate a room using infrared LEDs. That light is invisible to the eye, but some infrared wavelengths reach a phone camera's sensor and appear as a faint white or purple glow on screen. Findy provides a viewing mode intended to make such sources easier to notice in a dark room.

Infrared LEDs on a camera emit light; some reaches the phone sensor but an infrared-cut filter blocks much of it, so visibility varies by phone.
An infrared-cut filter blocks much of the light. What gets through depends on your iPhone.

C. Wi-Fi and local-network scanning

When you are connected to a Wi-Fi network, other devices on that same network are often reachable. Findy looks at the network you are on and reports what it can observe: which addresses respond, which services they advertise over Bonjour, and which respond on ports commonly used by IP cameras and recorders (RTSP and the vendor control and web ports).

The phone sees devices on the Wi-Fi it has joined, but not devices on a separate network, powered off, or wired only.
Findy sees the devices on the Wi-Fi network it has joined.

What Findy can observe

Device discovered is not camera identified

These are different claims and Findy keeps them separate. A device named IPC-1234 advertising a video service is genuinely worth investigating. A device with no name and no recognisable service is simply unidentified — and most home and hotel networks are full of those.

Findy marks each discovered device either as ordinary or as showing camera-related indicators, and shows the specific reason it was marked. There is no "confirmed" state and no certainty score.

How network results are marked
LabelWhat it means
OrdinaryNothing Findy observed about the device is associated with cameras.
Shows camera-related indicatorsOne of the checks below matched. Findy totals these and reports the count as the number of suspicious devices.

The reason shown beside a marked device is one of the following:

Findy shows the reason behind every flag. Be aware that a device whose name matches a manufacturer known for cameras is flagged on that basis alone — many such manufacturers also make televisions, doorbells and routers, so treat a name-only match as a starting point rather than a finding.

D. Bluetooth discovery

Findy lists Bluetooth Low Energy devices that are advertising nearby, and shows an estimated distance and a direction arrow calculated from the received signal strength. It also watches, in the background, for a device that keeps reappearing near you across different places — the pattern that suggests an item tracker is travelling with you rather than simply being nearby.

Signal strength rises as the phone moves closer to a device, but a wall between them distorts the reading; it is a warmer or colder guide, not a position.
Signal strength rises as you approach, but walls and bodies distort the reading.

Try it: warmer or colder. Move the phone and watch the signal — the bar is all you get, and it only tells you the direction to keep moving.

Weak signal — the device is somewhere in range, but you cannot tell where. Stronger — you are moving the right way. Keep going. Strong — you are close, but a wall could still be fooling the reading. Strongest here — now look. The app has taken you as far as signal can.

Bluetooth discovery finds devices that are

E. Magnetometer checks

The iPhone's magnetometer measures magnetic field strength. Electronics containing motors, speakers, shielding or magnets distort the local field. Sweeping the phone slowly across one specific object, and comparing against a baseline taken away from electronics, can reveal that the object contains more hardware than it appears to.

A flat baseline reading spikes when the phone passes over an object with electronics inside; ordinary objects also spike.
A spike above baseline indicates hardware nearby.

How to take a reading that means something

  1. Remove magnetic phone accessories, cases and stands.
  2. Establish a baseline well away from electronics and metal.
  3. Move slowly around the specific object you are inspecting.
  4. Repeat the measurement to check the reading is stable.
  5. Compare several sides of the object rather than one face.
  6. Inspect the object visually before concluding anything.

Why several methods instead of one button

Each method above works under different conditions. Lens reflection needs the right angle. Infrared needs the camera to actually use infrared. Network scanning needs the device to be on your network and powered on. Bluetooth needs it to be advertising. Magnetometer readings need a specific object to test.

A device that one method does not surface is often visible to another, which is why Findy uses several and presents its output as evidence to interpret rather than a single verdict.

See how we test these claims

Last reviewed 2026-07-23 · Reviewed by the Findy team at Flaps Apps.