Sensor Toolkit: Lux, dB, Level

Sensor Toolkit puts five everyday measuring tools on your phone, each built on a sensor the phone already has. Open the app, tap a tile, and the tool is ready. No account, no sign-up, and nothing your sensors read ever leaves the phone.

LIGHT METER
• Live illuminance in lux on a gauge from 1 to 100,000 lux
• Brightness band at a glance: Dark, Dim, Indoor, Bright, Daylight, Direct sun
• Exposure Value (EV) with selectable ISO 100 to 1600, for photo and video
• Min, average and max of the session, plus a reference table of typical lux values

SOUND METER
• Live noise level in decibels with min, average and max
• Level band from Quiet to Dangerous
• The microphone is used only while you measure. Nothing is recorded or saved.

COMPASS + LEVEL
• Compass with heading in degrees and cardinal direction, tilt compensated
• Bubble level with the tilt of both axes in degrees
• One tap switches between the two

SCREEN RULER
• Measure small objects directly on the screen, in centimetres or inches
• Uses the real pixel density of your display, with a one-time calibration against a card or coin for exact results

FLASHLIGHT + SOS
• Torch on and off with one large button
• SOS light signal in Morse code
• Brightness control on phones that support torch brightness (Android 13 and later)

MADE TO BE USED
• Light and dark theme, following your system setting or your own choice
• 20 languages
• Works on phones and tablets
• A sensor your device does not have is named clearly instead of showing a dead screen

HONEST SCOPE
These tools read your phone's built-in sensors, so they are handy references, not calibrated instruments. The sound meter shows an approximate level, not a certified sound pressure reading. The compass depends on your phone's magnetometer and on metal and magnets nearby. Accuracy varies between devices. The SOS signal is a light pattern only; the app does not call or message anyone.

PERMISSIONS
• Microphone: asked the first time you tap Start in the sound meter, and only there. Every other tool works without it.
• No camera permission, no location, no contacts, no storage access.

PRICE
Free, with one small banner ad at the bottom of the screen. No full-screen ads, no subscription.

Recent changes:
First release. Five tools in one app:
• Light meter with lux, EV and ISO
• Sound meter in decibels
• Compass and bubble level
• Screen ruler in cm and inches
• Flashlight with SOS signal
Light and dark theme, 20 languages.