Booth Assist

Built by a DJ for DJs: a number you can trust on one dark screen, related tempos ready for half-time, double-time, and polyrhythmic blends, and a sound level meter riding alongside. Nothing in the way. Most BPM apps are built to be downloaded, not used: free with ads, upsells standing between you and the number you came for, and readings that wander every time the kick drops out. Booth Assist is the opposite. Pay once and it is yours: no subscriptions, no ads, and every update free. No account and no data collection: audio is analyzed live on the device and never recorded. MADE BY A DJ, MEASURED LIKE IT MATTERS The detector was built and tuned by a working DJ against their own library, then scored against professionally analyzed two-decimal BPMs on a ~300-track test set spanning house, minimal, techno, DnB, and more. The results: 86% of the full set reads within 1 BPM of truth, 92% on club genres, and the median error on correct locks is 0.01 BPM. The same numbers hold under simulated booth conditions like echo, crowd noise, and muffled highs. Core techniques are adapted from published beat-tracking research and re-tested on real music before anything ships. WHO IT IS FOR Vinyl DJs who want a live tempo readout without touching a laptop. Hybrid DJs bridging turntables and CDJs mid-set. Digital DJs playing B2B with vinyl friends: read the record's tempo in seconds and dial it into your deck. Promoters, production staff, and sound engineers who want a quick secondary level check, inside the venue and out. BUILT FOR THE BOOTH Night mode is minimal, dim, and red: legible to dark-adapted eyes and discreet enough not to light up the booth. Day mode flips to bright white with heavier type for daylight sets and outdoor stages. Either way, the number is designed to be read across a room. MORE THAN ONE NUMBER Related tempos: live 2:1 and 1:2 readouts for double-time and half-time blends, plus 4:3, 3:4, 3:2, and 2:3 for polyrhythmic mixing. Pin a tempo with a long-press so the detector cannot override it, or tap it in yourself. Sound level meter: an estimated A-weighted reading with peak hold and a calibration slider to match a meter you trust. Your display, your rules: hide either readout to go full screen with the other, and show whole numbers, tenths, or hundredths. Locks in about ten seconds, refines to two decimals the longer it listens, and never fakes certainty: no readable tempo means the display says so. ABOUT THE dB METER iPhone microphones saturate around 100 dB, so above that Booth Assist shows an honest floor like "97+" instead of a made-up number. It is not a replacement for a calibrated booth meter and not a tool for sound-ordinance compliance. Use it to check levels around and outside the venue, next door, or in the booth when the reading sits confidently below 100 dB.