ChirpHound 4.0 is our biggest update ever, built around one truth: the beep you're hunting only sounds once a minute. • Chirp Trail — every new chirp gets a verdict: WARMER or COLDER than the last one, with the dB change and a trail of recent chirps. The hot-and-cold game finally works between chirps. • Truer measurements — we now measure the whole chirp, not a single instant, so every dB reading and frequency estimate is more accurate. • Hearing Assist — can't hear high-pitched beeps? Your phone can. Screen flash and torch blink the moment a chirp is heard, spoken guidance tells you warmer or colder, and with headphones on, a low-pitched tone you CAN hear tracks the signal. • Device Dossier — ChirpHound now names the likely device ("1 chirp every ~40 s at 3.2 kHz — smoke alarm low battery"), shows its evidence and sources, and gives you the exact fix. • Tap-to-Mark — beep too faint or muffled for the mic? Tap when you hear it, and ChirpHound still decodes the pattern and identifies the device. • Sonar Mode — a full-screen, one-handed hunting display for when you're on the step-stool. And when you find it, tap Found It for the moment you've earned — your hunt is saved with the device, the room, and how long it took. • Sharper spectrogram — see your listening band, see exactly when chirps landed, and freeze the display to inspect a beep you missed. Still 100% private and offline. No accounts, no analytics, no network — ever.

Version 3.1.1 fixes a dead end when a hunt finds nothing. • A hunt only listens to the narrow band of the selected preset. When no chirps are detected, ChirpHound now names the exact band it is listening to instead of only telling you to keep waiting. • Added a one-tap "Scan 400 Hz – 6 kHz instead" action to the live chirp log, so a beep outside the current preset's band can be found with Auto Discover without guessing the right preset first.

Version 3.1 makes ChirpHound easier to start, easier to learn, and much more effective with intermittent sources. • Rebuilt first-launch layout with a pinned, accessible Start hunting button. • Auto Discover ranks repeatable tones across 24 bands from 400 Hz to 6 kHz. • Room Finder can wait for the next actual chirp and capture its peak for each room. • New offline Signal Lab with 18 original synthetic practice scenes. • New persistent Hidden Source Checklist with 43 practical search checks. • Expanded Chirp Field Guide from 34 to 44 original visual plates. • Optional keep-awake mode for long 30–60 second chirp intervals. • New current-version screenshots and additional iPhone/iPad layout validation.

Version 3.0 is a major safety, reliability, and field-work upgrade. • Correct emergency guidance for three-beep smoke/fire and four-beep carbon-monoxide patterns. • Stronger burst analysis with repetition, consistency, and inter-burst timing evidence. • Live calibration progress and microphone route, format, tonality, and relative-level diagnostics. • Resilient audio interruptions, route changes, unavailable-input handling, and live preset retuning. • Better Dynamic Type, VoiceOver, responsive layouts, and Reduce Motion support. • Smoother live monitoring with substantially fewer unnecessary screen updates.

Version 2.1 • New Sweep Plan turns live chirps, interval evidence, burst groups, and Room Finder readings into a ranked field action plan. • New Chirp Field Guide adds bundled offline reference plates for alarm patterns, room-sweep technique, frequency bands, and source-backed safety notes. • Current screenshots and metadata have been refreshed to show the app in use without stale purchase wording. • Better review notes, updated source-backed documentation, and a new screenshot capture flow for iPhone and iPad.

This update sharpens the interface: the iPad layout now uses a centered, comfortable reading width instead of stretching edge to edge, so every screen reads as a clean column. iPhone is unchanged; still fully on-device.

ChirpHound 2.0 — a pro upgrade for tracking down that chirp, still 100% on-device. • Room Finder: take labelled dB readings room by room and get a ranked, confident verdict on which room the chirp is actually in. • PDF hunt report: export a full report — including the room survey — to share with a landlord or technician. • Insights dashboard: totals, records, urgent count, and a per-source breakdown. Plus the same live narrow-band detection, warmth gauge, haptic "getting warmer" ramp, and spectrogram. No account, no network — every sound is analyzed on your device.

Version 1.1 (build 3) • Beep Guide — a new offline reference tab listing 20 chirp signatures across smoke alarms, CO detectors, appliances, UPS units, smart locks, and leak sensors. Every entry includes the burst count, interval, what the pattern means, and exactly what to do. Sourced from UL 217, UL 2034, NFPA 72, and manufacturer support pages. • Burst Analyzer — ChirpHound now counts the number of rapid beeps per group (burst size). 1 chirp/burst = low battery. 2 chirps/burst = end-of-life (replace the unit). 3 chirps/burst = fault/malfunction. 4 chirps/burst = CO emergency. The burst count is shown in the chirp log and used by the Pattern Decoder. • Smarter Pattern Decoder — the Hunt Detail screen now combines burst-count analysis with interval analysis for a more precise diagnosis. Each result includes an explicit "What to do" action step. Urgency-coded: danger (red border) for CO emergency or water leak, warning (amber) for low-battery and end-of-life, info for appliances. Earlier 1.1 additions (if upgrading from 1.0): • Pattern Decoder for inter-chirp interval analysis. • 5 new presets (520 Hz bedroom alarm, water/flood sensor, Nest Protect, medical pendant, CO high-pitch). • CSV export from History tab.

Version 1.1 • Pattern Decoder — after two or more chirps, the Hunt Detail screen now tells you what the detected interval likely means: low-battery smoke alarm, CO alarm approaching end-of-life, UPS on battery, smart-lock low, appliance chime, and more. Confidence is shown as "likely" or "possibly" with a supporting explanation. • 5 new presets — 520 Hz low-frequency bedroom alarm (NFPA 72 sleeping-area standard; Lifetone/Gentex), water/flood leak sensor, Google Nest Protect low-battery pattern, medical alert pendant, and one additional CO band. Now 15 curated presets. • CSV export — tap the share icon in History to export your complete hunt log as a CSV file compatible with Numbers, Excel, or any spreadsheet. Includes date, preset, band, duration, chirp count, median interval, mean bearing, and your note. • Version number now reads from the app bundle instead of a hardcoded string. • Bug fix: toolbar button on History tab was missing in 1.0.