Light Meter

The ambient light sensor sits next to the front camera and measures the light falling on the screen. Point the screen at the source, not away from it. The accuracy is domestic: fine for checking a workplace, not for photometry.

The instrument uses the phone's ambient light sensor and shows the value in lx.

• A large number, readable at arm's length.

• A chart of the last minutes — you can see it rise or fall.

• Minimum, average and maximum per session, reset with one button.

• A threshold with sound: an alert when the value goes above it.

• A table of everyday equivalents to compare your reading against.

• No ads. Under a megabyte. Works without internet.

Saved measurements are a one-time purchase, not a subscription. The scale, the chart, the threshold with sound and the table stay free for good.

The app sends anonymous usage statistics; you can turn this off in settings.

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