Bubble Level: Spirit, AR Ruler

Bubble Level is a precise spirit level, an on-screen ruler, an angle finder and an AR ruler in one small, fast app. The level reads your device's gravity sensor for smooth, jitter-free tilt, turns green the instant a surface is level, and shows the exact angle to a tenth of a degree. The ruler is calibrated to your screen, so a centimetre on glass is a centimetre in real life. No account, no sign-up.

BUBBLE LEVEL / SPIRIT LEVEL

- Two-axis spirit level driven by the gravity sensor, smooth, no shake or jitter

- Surface mode, lay the phone flat for a bullseye that centres when level

- Edge mode, stand the phone on a side to level a shelf, frame, picture or wall

- Turns green the instant a surface is level, with a clear numeric readout

- Roll, pitch and slope shown at a glance

- Optional tone the moment the surface is level (off by default)

ANGLE FINDER / INCLINOMETER

- Measure any angle or slope, clinometer and protractor in one

- Read incline in degrees or percent grade for ramps, roofs, stairs and pipes

CALIBRATION

- One-tap calibrate against a known-level surface to zero out your device

- Reset returns to the factory zero. your calibration is remembered

SCREEN RULER

- On-screen ruler with centimetres down one edge and inches down the other

- Calibrated to your display's real DPI for true-to-size measurements

- Credit-card calibration fine-tunes the scale on any phone or tablet

AR RULER

- Measure real objects with the camera, like a tape measure through the lens

- Aim the crosshair at a surface and tap + to place measure points

- Live distance while you aim, several measurements in one picture

- Switch between centimetres and inches

- Share or save the result as a photo with all measurements on it

The AR ruler needs Google Play Services for AR (ARCore) and only appears on devices certified by Google. On devices without ARCore, including many China-market models from Oppo, Honor or Huawei, the AR button hides itself automatically. Level and ruler work on every device.

DESIGN & LANGUAGES

- Clean Material 3 interface with a true-black AMOLED dark theme, edge-to-edge

- Works in portrait and landscape, phone and tablet

- Available in more than 70 languages, pick yours right in the app

TYPICAL USES

Hanging pictures, shelves and mirrors. Levelling furniture, appliances and brackets. Checking a table, worktop or floor. Measuring small objects without a tape measure. Sizing a phone case or screen protector. Straightening frames on a wall. Levelling a tripod, TV mount or washing machine. DIY, woodworking, carpentry and quick repairs around the house.

PERMISSIONS

- Camera, used only for the AR ruler (a photo is saved only when you share or save a measurement)

- Internet, used only to load ads (a small banner and, now and then, a full-screen ad)

PRIVACY

No account. No sign-up. No subscription. No in-app purchases. Anonymous usage statistics via Firebase Analytics, no personal data. Ads (a small banner and, now and then, a full-screen ad) are served via AdMob, see the Data Safety section for AdMob's third-party disclosures. Made in Switzerland by an independent developer.

Get in touch: nils.roethlisberger@gmx.ch

Popular uses: level a caravan, camper or RV on the campsite, check shelves, frames and furniture, measure roof pitch and slopes in degrees or percent, and measure objects with the AR ruler. A digital spirit level with degree readout for DIY and construction.