Shutterguard

Check the room before you settle in.

Shutterguard uses your iPhone's flash and camera to look for lens-like reflections. Free to use. Nothing leaves your phone.

Download Shutterguard on the App Store
Scan result: a red circle marks a reflection that may be a camera lens

Hotel rooms, fitting rooms, restrooms. About a minute each.

Each scene comes with a suggested scan order. The results show what was found and leave the judgment to you.

  1. 1

    Pick a scene

    Hotel, fitting room, public restroom, clinic or spa, rental check-in, or ceiling. Each has its own route.

  2. 2

    Follow the prompts

    Close the curtains or dim the lights for best results. When a bright spot shows up, move closer or change the angle to confirm it.

  3. 3

    Read the clues

    Each reflection is marked with likely causes. A higher score means more clues, not proof of a hidden camera.

Home screen with six scenes and a suggested scan order (app shown in Traditional Chinese)
Result screen with the clue score and number of reflections found (app shown in Traditional Chinese)

Free to start. Upgrades are one-time purchases.

No subscriptions. Buy once, keep it.

Free

Free

Try it out

  • Photo-based lens reflection check
  • Infrared check (lights off)
  • Keeps your last 10 scans
One-time

Pro

Pro

For frequent travelers who want a fuller check

  • Sweep-mode lens check: the flash pulses quickly, then confirms bright spots up close automatically
  • Bluetooth, ultrasonic noise and same-network Wi‑Fi camera checks
  • Magnetic field reading for reference (not scored)
  • Discreet mode and arrival reminders
  • Unlimited history, full evidence photos, export

Pro+

Pro+

iPhone models with LiDAR only

  • Everything in Pro
  • 3D room map to place clues in context

Pro+ includes Pro, so there is no need to buy both. Prices vary by region and are shown in the App Store. Requires an iPhone with iOS 17 or later. The app interface is currently in Traditional Chinese.

What it cannot do

Lens detection relies on the flash reflecting off a lens. If there is no reflection to catch, no method will find it.

  • Covered or powered-off lenses

    A camera that is off, covered by metal, or only runs on a schedule gives nothing to detect.

  • Deep pinholes and anti-reflective coatings

    When the hole is much deeper than it is wide, or the lens has an advanced coating, the reflection is very weak.

  • Too much light

    Daylight or a brightly lit room drowns out the reflection. Close the curtains or turn off the lights first.

  • Too far away

    Beyond about 2 meters the reflection is too faint to separate from noise.

  • Steep angles

    A lens reflects most strongly within about 10 to 20 degrees of straight on. Scanning from several angles helps.

  • Devices built to avoid detection

    Electronic shutters and special housings can defeat optical detection entirely.

Treat the result as a reference, not a guarantee of safety. If you have concerns, contact local police.

The in-app privacy explanation screen (Traditional Chinese)

Your data stays on your phone

  • No uploadsScan history, photos and Bluetooth device lists never go to any server. The developer cannot see them.
  • No accountNo sign-up, email or name required.
  • No ads or trackingNeither the app nor this website includes ads, trackers or analytics.
Read the privacy policy