Repeat Pass Compare two saved acoustic traces position by position to see agreement, disagreement and uncertain taps. 1. Mark at least three positions, calibrate for the wall, and save two traces using the same positions. 2. Open History, tap Compare, select the passes, and confirm matching positions and calibration. 3. Reverse the second pass if needed, inspect each position, and share the comparison. An illustrative example is available. Repeatability does not prove a stud or a safe mounting point. Acoustic taps cannot identify wiring, pipes or other hidden hazards. Independently verify before drilling. Different trace lengths are rejected; low-confidence taps and edge classifications remain uncertain even when labels match.

Wallrap 1.3 adds Mount Check for saved trace sessions. Open a saved wall trace to see the strongest candidate anchor point, a confidence score, spacing evidence, practical verification steps, and clear warnings before drilling or hanging heavy objects. This update also refreshes App Store screenshots, support copy, and review notes so the product page matches the current app.

HEADLINE — Edge-Lock live stud-center finder. New Wallrap/Models/EdgeLock.swift: pure value type EdgeLockTracker (unit-testable, KnockRun/StudPredictor pattern) holding an ordered buffer of recent (index, Classification) knocks. Exposes enum CenterState { searching, approaching(side:solidRun:), edgeCrossed(EdgeKind), centered(confidence:) } computed from the trailing run: it finds the most recent contiguous high-confidence solid run, requires a flank (hollow/edge) immediately before AND after it (the leading hollow-to-solid and trailing solid-to-hollow edges), and takes the argmax-confidence s

Wallrap 1.1 Snap-to-Stud gauge (Listen mode) The classification chip now accumulates the last 3–5 knocks in a rolling window. When they all agree with high confidence, a "STUD FOUND" or "CAVITY CONFIRMED" banner replaces the idle prompt — far more decisive than reading individual flickers. A row of colored dots shows the chronological knock sequence so you can see exactly how the window built up. Stud spacing predictor (Trace mode) After a trace, Wallrap now analyses the pattern of solid-segment gaps to infer whether your wall is framed 16" on-center (the US residential standard per IRC R602.3) or 24" on-center. A confidence bar and one-line summary appear beneath the map strip. The predictor is honest about uncertainty — it shows "?" when the data isn't clear enough. Session history + CSV export Completed traces can now be saved with an optional room note. The History tab shows every saved session with its wall map, knock counts, and spacing estimate. Tap any session to export the full knock-by-knock data as a CSV file (timestamp, centroid, band energies, label, confidence) via the iOS share sheet — useful for comparing walls or logging a project over time. All data stays on your device. No accounts, no network, no subscriptions.