JBT PRoLOG vs Trueline

The app allows you to connect with your JBT PRoLOG devices via Bluetooth Low Energy. You can check their state, start measurements and configure your channels manually or apply preconfigured settings.

Trueline turns your iPhone into a level that behaves like a real instrument — quiet, readable, and honest about what it measures. Free: • Auto-switching modes — on edge or plumb you get a vial with a signed degree readout; laid flat it becomes a 2-axis bullseye surface level • Read in degrees, slope %, or roof pitch (rise per 12) • One-tap calibration • HOLD freezes a reading you can't see from where you're standing • ZERO for relative angles — the angle between two surfaces • Haptic snap and a green edge glow the moment you're level • Fully offline, no account Pro — one payment of $6.99, no subscription: • AR laser level: project gravity-true level and plumb lines onto the wall and hang a whole row of frames in one pass • Named angle presets — 4/12 and 6/12 roof pitch, stair rake, 2% drainage • Precision tolerance down to ±0.1° • 5 instrument themes • No ads Pay once, yours forever. No subscription, no sign-in, and nothing leaves your phone.