Tilt: Bubble Level & Ruler

Tilt is a bubble level and a ruler for the jobs around a home: a shelf, a row of
pictures, a washing machine that walks across the floor, a door that will not
stay shut.

A CALIBRATION THAT DOES NOT LIE

Most level apps calibrate by "set this as zero". That stores the phone's own
error and the slope of whatever it was lying on, and subtracts both from every
reading afterwards. Calibrate on a table a third of a degree out, and every shelf
in the house reads a third of a degree wrong while the app says 0.0°.

Tilt takes two readings in the same spot, with the phone turned round end for end
between them. The slope of the surface changes sign between the two readings and
the phone's own error does not, so the average is the phone alone. The surface
does not need to be level. Each side of the phone is calibrated on its own,
because a camera bump or a rounded edge is a fact about one side.

THE LEVEL

• A round bubble with both angles when the phone lies flat
• A tube level when it stands on any edge, in portrait or landscape
• The angle shown to a tenth of a degree, with the fall in mm per metre or
inches per foot
• Hold, to freeze the reading when you cannot see the screen
• A tick you can feel when it comes level

THE RULER

• Millimetres, or inches to the sixteenth, down the long side of the screen
• Two lines you drag to the ends of what you are measuring, so the edge of the
phone's case does not matter
• Calibrated once against a bank card, which is 85.60 mm long everywhere

SAVED

Keep a reading or a length with a note to say where it was, and find it again in
one list.

WHAT IT DELIBERATELY DOES NOT DO

• No camera. The level is the phone's gravity sensor and the ruler is the screen.
• No location, no account, no sign-in.
• Nothing to allow: the app never shows a permission request.

PRIVACY

Your saved readings and your calibration are stored on this phone and nowhere
else. The app has no server. Android cloud backup is switched off for it, because
a calibration belongs to one phone and would be wrong on the next.

The app shows ads. The only data that leaves your device is what Google AdMob
needs to show them, and it never includes anything you typed.

Full policy: https://dash-fusion.github.io/privacy/list-level