Plumb Bob

Plumb Bob turns your phone into a live plumb line that swings to true vertical the moment you hold the device against a wall, a post, a door frame, or a fence panel. The line is driven directly by the gravity vector, and the deviation from vertical is printed on the screen in degrees with one decimal of precision.

What you can do:

- Hold your device against a vertical surface and watch the plumb line settle. When the line matches the reference vertical drawn on screen, the surface is plumb.
- Read the deviation from vertical in degrees with one decimal so you know exactly how far off plumb you are, and in which direction.
- Rely on the dedicated gravity sensor on devices that ship one. On devices without a hardware gravity sensor, Plumb Bob falls back to a smoothed accelerometer reading so the line stays steady on almost any Android phone or tablet.
- Start measuring the second the app opens. There is no home grid, no wizard, no promo screens.

Why choose Plumb Bob:

- Fully offline. The app never opens a network socket.
- Zero permissions. The manifest declares no runtime permissions, no INTERNET, no location, no storage, no camera, no microphone.
- No ads and no advertising SDK.
- No in-app purchases and no billing SDK.
- No analytics, no tracking, no crash reporting SDK.
- Small install size and quick startup on modest hardware.
- Clean Material Design surface with automatic day and night themes that follow your system setting.

Plumb Bob is designed for installers, carpenters, homeowners, hobbyists, and anyone who needs to verify vertical alignment without unpacking a string-and-weight plumb bob. Compatible with Android 7.0 (API 24) and newer.