ProLevel: Angle & Slope

Precision Spirit Level is a digital spirit level, angle finder, and slope calculator for tradespeople and DIYers who need a reading they can trust the first time. Calibrate once against any known-flat surface, and every reading after that — on every job — stays accurate. No guesswork, no drift, no second-guessing your tools. WHAT YOU GET FREE • Surface Level — a classic bubble level for flat surfaces, screen up • Edge Level — a plumb / vertical level for walls, frames, and studs • Instant calibration against any reference surface you trust • Light, dark, and system theme support UNLOCK FOR $1.99 — ONCE, NO SUBSCRIPTION • Slope % — grade readings in degrees and percent, for drainage, ramps, and grading work • Project Log — save labeled readings with timestamps and photos • CSV export — turn saved readings into a client-ready report BUILT LIKE A TOOL, NOT AN APP Precision Spirit Level fuses accelerometer and gyroscope data through a tuned complementary filter for a stable, drift-resistant bubble — then lets you zero it out against a surface you trust. That's the whole idea: calibrate once, trust every reading. OFFLINE. NO ACCOUNT. YOUR DATA STAYS ON YOUR PHONE. No sign-up, no login, no internet connection required. Every reading, calibration offset, and saved log entry stays on your device — nothing is ever uploaded, tracked, or sold. WHO IT'S FOR Carpenters, framers, tilers, landscapers, plumbers, and anyone who needs a reliable digital level, angle finder, or inclinometer on the phone already in their pocket. $1.99 once. No subscription, no ads, no artificial free-tier limits designed to nag you. Calibrate once. Trust every reading.