Ruler Kit: Protractor & Level

No tape measure? Your screen becomes the ruler.

Ruler Kit puts a ruler, a protractor and a bubble level in one app. Hold an object against the screen, drag the cursor lines to its edges, and read the length instantly. Got a credit or transit card? Calibrate accurately in one tap — no physical ruler needed.

■ What you can do
• Screen ruler — cm / mm / inch, drag two cursor lines to an object's edges
• One-tap card calibration — match a card (85.6 mm) or a real ruler and the screen measures true
• Protractor — drag two arms to measure any angle
• Bubble level — check tilt and level instantly (sensor-based)
• Save measurements + see the latest on a home-screen widget
• Dark mode, four languages

■ Privacy first
No camera, no location, no account. Measurements stay entirely on your device. Nothing is sent to a server.

■ Honest about accuracy
Measurements are approximate, based on your screen's physical size, so calibrate once for accuracy. This isn't a replacement for precision instruments.

Pull out the ruler, protractor and level that live in your pocket.