Bubble Level

Hanging a picture frame, mounting a shelf or curtain rail, leveling a washing machine or fridge, setting up a camping table — Bubble Level turns your phone into a real spirit level you can check right now.

📐 Surface & Edge Modes, Auto-Switching
Lay the phone flat and you get Surface Mode: a bubble moving inside a circular target with X/Y pitch and roll angles shown together. Stand the phone up or press its edge against an object and it switches to Edge Mode: a horizontal tube bubble just like a classic spirit level, with a single angle reading. The app detects your phone's orientation and switches automatically — surface mode for tables and appliance tops, edge mode for frames and shelves.

🎯 Precise 0.1° Readings with Level Feedback
Accelerometer data is smoothed with a low-pass filter for a steady, jitter-free 0.1° reading. When the tilt falls within your chosen tolerance (default ±0.5°), the bubble changes color and the phone gives a short vibration — so you can level things by feel without staring at the screen.

⚙️ Zero-Point Calibration
Working on a surface that isn't perfectly flat? Save the current tilt as your new 0° reference. The calibration offset is stored permanently on your device and survives app restarts.

✋ HOLD Button
Freeze the current angle reading on screen with one tap, so you can read the value even after lifting the phone off the surface.

🚫 No Interruption Ads
The #1 complaint about competing level apps is full-screen ads popping up every 10-15 seconds. Bubble Level shows only a single small banner ad at the bottom of the screen — never a full-screen or popup ad that interrupts your measurement.

🌐 Fully Offline, Minimal Permissions
No account or login required, and the core leveling feature works with no internet connection at all. The app never requests sensitive permissions like location or camera.

Other features
- Switch units: degrees (°) or tilt percentage (%)
- Toggle vibration feedback
- Two sensitivity modes (Stable / Fast)
- Korean and English support
- Keeps the screen on while measuring

No tools needed — just your phone, right now.