Bubble Level & Inclinometer

Bubble Level is a precision spirit level and inclinometer that behaves like a real instrument.

Lay your phone on a shelf and it reads the surface at a glance: a liquid bubble that merges and parts like the real thing, and a large angle that turns to read straight along the slope. Reach level and the whole screen goes green, with a quiet pulse you can feel through the case — so you can keep your eyes on the work instead of the phone.

GREEN MEANS LEVEL
No squinting at a bubble between two lines. At true level the screen answers with one unmistakable color and a single confirming pulse — a reading you can take from across the room, or without looking at all.

IT KNOWS HOW IT IS HELD
Lay it flat to read a surface. Stand it on end against a door frame to check plumb. Set it on its long edge along a beam, the way you would lay a real spirit level. The app switches between surface and edge by itself, and the reading stays upright and legible at every quarter turn.

TWO INSTRUMENTS IN ONE
Modern gives you the liquid bubble and one large angle, rotated along the slope. Classic gives you the bullseye and the twin vials of a workshop level, with separate X and Y readings. One tap swaps the whole instrument. Both read the very same sensors.

LOCK ANY SLOPE AS YOUR ZERO
Tap once to store the angle you are on as the new zero. Now match it anywhere: a run of pipe to the same fall, a second shelf to the first, a ramp to the drawing. Green while you are on the line, red the moment you drift off it, and a number telling you by how much.

READ THE NUMBER YOUR TRADE WORKS IN
Degrees, percent slope, millimeters per meter, or roof pitch as a ratio to twelve. Switch units in one tap from the corner of the screen, and turn on tenths when the job is fussier than a whole degree.

CALIBRATE ONCE, TRUST IT AFTER
Most handsets read a fraction out of true. Rest the phone on a surface you trust, hold still, and the guided calibration sets true zero — separately for flat and for upright, because the two are not the same error. Stored until you reset it.

THE SMALL THINGS
• A Quick Settings tile — one swipe and a tap, from any screen
• Keep-screen-on, so the display never dims mid-measurement
• Haptic confirmation you can switch off
• Spoken readings for TalkBack, including the direction of the tilt
• The measurement itself needs no signal: it comes from your phone's own sensors, so it works in a basement, a new build or out of range

WHAT PEOPLE USE IT FOR
Hanging pictures, shelves and mirrors straight. Leveling a washing machine, a fridge, a pool table or a tripod. Checking the fall on a pipe, a gutter, a driveway or a drain. Squaring a door frame. Reading a roof pitch. Leveling a caravan, a trailer or a boat trailer. Carpentry, tiling, masonry, decking, photography, and the shelf that has annoyed you for a year.

If you came looking for an inclinometer, clinometer, angle finder, angle meter, tilt meter, slope gauge, gradient meter, digital level, level tool or surface level app — this is that, with a reading you can take at a glance.

A fine instrument, built into your phone.